Proceedings - SPIE Digital Library

Jump to Content

Increase text size Decrease text size

SPIE DL Tab

SPIE Proceedings Tab

SPIEDL Journals Tab

SPIE eBooks Tab

My Subscription | My Email Alerts | My Article Collections

BROWSE PROCEEDINGS

Proceedings

BROWSE JOURNALS

Journals

BROWSE SPIE eBOOKS

SPIE eBooks

SUBSCRIPTIONS & PRICING

GENERAL INFORMATION

Search Volume | RSS Feeds

RSS
Previous Volume Next Volume

Volume 6279 27th International Congress on High-Speed Photography and Photonics

Xun Hou, Wei Zhao, Baoli Yao January 2007

Conference Location: Conference Date:

SECTION LISTING

Add

Add Items to Cart

View

View Items in Cart

SELECTED: Export Citations | Show Only | Show All | Show/HideHide Summaries | Add to MyArticles | Email

back to top

Front Matter

Select this Article OPEN ACCESS		Front Matter Proceedings of SPIE Proc. SPIE 6279, 627901 (2007); http://dx.doi.org/10.1117/12.726271 Online Publication Date: Jan 17, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This PDF file contains the front matter associated with SPIE Proceedings Volume 6279, including the Title Page, Copyright information, Table of Contents, Introduction, Congress Awards, Exhibitors, and the Conference Committee listing.

back to top

Plenary Papers

Select this Article		Photonics and laser optical diagnostics for investigations of high-speed transient processes Manfred Hugenschmidt Proc. SPIE 6279, 627902 (2007); http://dx.doi.org/10.1117/12.725052 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The present paper gives an overview on laser optical diagnostics used for studies of fast, transient phenomena. Examples are cited, related to investigations of high power nonlinear laser radiation interacting with materials. These quasi explosively developing effects require photonic techniques with highest temporal and spatial resolution, such as provided by short-pulse and ultra-short pulsed lasers. As discussed, optical methods are useful for optimization of industrial production processes and research topics. Advantages of coherent light in classical optical methods for beam deflection or phase measurements are evaluated and compared with disadvantages, due to superimposed speckle patterns causing noise and loss of information in higher parts of spatial frequency spectra. As a major breakthrough, features of holographic threedimensional reconstruction of optical wave-fields are emphasized. Selected examples provide a comprehensive evaluation of coherent optical diagnostic principles, as compared to non coherent techniques. Moreover, novel methods, using carreer-frequency photography are stressed in which case speckles themselves are carrying information to be measured. Further examples demonstrate the versatility and flexibility of ultra-short pulsed laser measurements down to the femtosecond- range (1 fs=10^-15s), whereby the Moire set-up chosen for demonstration can be substituted similarly by other optical techniques. Summarizing, it can be stated that lasers provide unique tools for highest resolution, highest accuracy measurements. Direct visualization, pump and probe techniques and other methods are adaptable to any industrial or research related requirements. As shown in the outlook, meanwhile achievable XUV attosecond pulses (1 as=10^-18s), generated by fs-lasers, open the door for future (so far not yet fully predictable) applications, also in the field of ultra high-speed diagnostics.

Select this Article		4DCapture/4DPlayer: evolving software packages for capturing, analyzing and displaying two- and three-dimensional motion data James S. Walton, Peter N. Hodgson, and Karen G. Hallamasek Proc. SPIE 6279, 627903 (2007); http://dx.doi.org/10.1117/12.725053 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In September 2002, during the 25^th Congress on High Speed Photography and Photonics, 4DVideo described a general purpose software application for the PC platform. This software (4DCapture^TM) is designed to capture, analyze and display multiple video sequences. The application extracts trajectories and other kinematic information from (highspeed) video streams. Since 4DCapture^TM was originally described, it has matured, and a second application (4DPlayer^TM) has been introduced to support the distribution and viewing of video streams and kinematic data acquired by 4DCapture^TM. 4DPlayer^TM is "freeware". It may be redistributed to third parties, but it may not be modified. 4DCapture^TM provides a structured environment for experimental data. Cameras are treated as transducers-that is, a source of technical data. The application provides an interface to the cameras for previewing the object-space, calibrating the images, and testing. This application can automatically track multiple landmarks seen from two or more views in two or three dimensions. Trajectories can be processed within the main application or they can be exported to a spreadsheet where they can be processed or passed along to a more sophisticated, data analysis application. 4DCapture^TM also incorporates a simple animation capability and a friendly (FlowStack^TM) user interface that assists the end-user to capture and treat image sequences in a natural progression. 4DCapture^TM employs the AVI 2.0 standard and DirectX technology. 4DPlayer^TM can be used to view multiple video sequences simultaneously and perform simple measurements of displacements and angles that vary over time. This application can detect and display the coordinates of landmarks previously identified by 4DCapture^TM that have been embedded in the video streams.

Select this Article		Historical development and application of ultra fast diagnosis based on image tube in XIOPM Wei Zhao, Xun Hou, and Jin-Shou Tian Proc. SPIE 6279, 627904 (2007); http://dx.doi.org/10.1117/12.725054 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Xi'an Institute of Optics and Precision Mechanics of CAS was founded in 1962, but the research activities on high-speed diagnosis in China can be dated back to 1958. The main goal of the Institute is developing some optical and opto-electrical diagnostic tools of transient phenomena. This paper describes the historical development and application of ultra fast diagnosis based on image tube in XIOPM.

Select this Article		High-energy x-ray imaging diagnostics of nanosecond pulse accelerators Graham W. Smith, Robert J. Hohlfelder, Alun J. Tribe, David E. Beutler, Roque R. Gallegos, Calvin L. G. Seymour, and Jon A. Thompson Proc. SPIE 6279, 627905 (2007); http://dx.doi.org/10.1117/12.725055 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract X-ray imaging has been undertaken on Sandia National Laboratories' radiation effects x-ray simulators. These simulators typically yield a single very short (<20ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad (Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.5 to 1.8MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and an evaluation of the capability of the spectrometer are presented.

Select this Article		Novel monochromatic x-ray generators and their applications to high-speed radiography Eiichi Sato, Rudolf Germer, Haruo Obara, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Mitsuru Izumisawa, Toshio Ichimaru, Kiyomi Takahashi, Shigehiro Sato, and Kazuyoshi Takayama Proc. SPIE 6279, 627906 (2007); http://dx.doi.org/10.1117/12.725056 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Novel monochromatic x-ray generators and their applications to high-speed radiography are described. The five generators are as follows: a weakly ionized linear plasma x-ray generator, a monochromatic compact flash x-ray generator, a super-fluorescent plasma generator, a cerium x-ray generator using a 3.0-mm-thick aluminum filter, and a 100micron-focus x-ray generator utilizing the filter. Using the linear plasma generator with a copper target, we observed clean K lines and their harmonics, and soft flash radiography was performed with pulse widths of approximately 500 ns. The compact monochromatic flash x-ray generator produced clean molybdenum K lines easily, and high-speed radiography was performed with pulse widths of approximately 100 ns. Using a steady-state cerium x-ray generator, we performed real-time angiography utilizing an image intensifier and a high-sensitive camera (MLX) made by NAC Image Technology Inc. with a capture time of 1 ms. Finally, real-time magnification radiography was performed by twofold magnification imaging using a 100micron-focus x-ray generator and the high-sensitive camera.

Select this Article		Recent advance in streak and framing cameras in Shenzhen University Junle Qu, Baoping Guo, Ji Li, Qinlao Yang, Jinyuan Liu, Lihong Niu, and Hanben Niu Proc. SPIE 6279, 627907 (2007); http://dx.doi.org/10.1117/12.725058 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, we report on the recent development of streak and framing camera techniques in Shenzhen University, such as soft X-ray streak image tube, synchroscan streak image tube, image intensifier and different kinds of newly developed electronic circuits. In particular, we present three different kinds of streak and framing cameras, including a soft X-ray streak camera with slit length of 30mm, dynamic spatial resolution of 15lp/mm and dynamic range of larger than 900; a specially designed synchroscan picosecond streak camera with a repetition rate of 1MHz, which can provide simultaneous time- and spectrum-resolved two-dimensional(2D) sampling information for biomedical imaging; and an 8 channel framing camera with exposure time of 3ns and dynamic spatial resolution of better than 20lp/mm.

back to top

Image Converter Streak and Framing Cameras

Select this Article		High-speed image converter instrument Engineering of VNIIOFI is 40 years old Vyatcheslav S. Ivanov, Yuri M. Zolotarevsky, Vladimir N. Krutikov, Vitaly B. Lebedev, and Grigory G. Feldman Proc. SPIE 6279, 627908 (2007); http://dx.doi.org/10.1117/12.725059 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A review of high-speed image converter instrument engineering in VNIIOFI during 40 years from the moment of Institute foundation up to this time is presented.

Select this Article		Development of streak cameras for time-resolved experiments at the advanced laser light source laboratory C. Martel, S. Fourmaux, C. Y. Côté, S. Magnan, L. Lecherbourg, and J. C. Kieffer Proc. SPIE 6279, 627909 (2007); http://dx.doi.org/10.1117/12.725063 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The Advanced Laser light Source (ALLS) infrastructure is a new state-of-the-art multi-beams femtosecond laser facility currently in operation at INRS near Montreal, Canada. Multi-beams experiments and pump-probe geometry lead to the need of synchronization instrumentation tools. The use of a wide range of energy radiation from hard x-ray up to infrared light on the ultrafast time scale requires the development of ultrafast detector diagnostics tools to study the emission spectrum of these sources. To fulfill these requirements, new streak cameras have been developed for ALLS facility. The SV streak camera is a simple and compact multi-purpose instrument that will be used for beams synchronization with picosecond time resolution and good spatial resolution. The FXR streak camera is dedicated to x-ray spectroscopy with sub-picosecond time resolution combined with a very high spatial resolution.

Select this Article		Femscan: the development of the image dissector to a tube with femtosecond time resolution J. R. Howorth, J. Milnes, and P. Yvernault Proc. SPIE 6279, 62790A (2007); http://dx.doi.org/10.1117/12.725064 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The Image Dissector was one of the first all electronic TV tubes and was described by Farnsworth in 1934. (Ref 1). Fifty years later, in 1983, more modern image dissectors were used to measure the electron bunch lengths in synchrotrons. The advent of modern computers and high-speed electronics enables these rather elderly tubes to be used in exciting new applications. This paper described how we have adapted the image dissector to enable the development of low cost instruments with exceptional bandwidth, sensitivity and sampling rate for optical signals.

Select this Article		Test of streak camera with high photoelectron beam density and energy Sergey M. Gurov, Petr A. Bak, Yury D. Chernousov, Pavel V. Logatchov, and Evgeny E. Pyata Proc. SPIE 6279, 62790B (2007); http://dx.doi.org/10.1117/12.725065 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Streak camera with spiral scanning will allow measuring a single light signal with duration up to ten nanoseconds with sub-picoseconds time resolution during all signal duration by means of using the whole 2D surface of screen. For creation such a streak camera it is necessary to have a high density of photoelectron beam in order to have small beam size and enough quantity of electrons in the resolution element. But the beam density increasing is limited by different effects including temperature relaxation. Quite the contrary in typical streak cameras the beam density is reduced down to single photoelectrons in the resolution element and then the number of electrons is integrated either on recurring signal or along streak. Another way is the significant increase of electrons energy. This idea has been realized in the streak camera with photoelectron energy up to 90kV and circular scanning by means of high quality RF cavity. The results of testing of this streak camera are presented. The design of streak camera with spiral scanning is presented.

Select this Article		Research of range resolution of streak tube imaging system Sining Li, Qi Wang, Jinbo Liu, and Yuhao Guang Proc. SPIE 6279, 62790C (2007); http://dx.doi.org/10.1117/12.725077 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Key factors that influence the range resolution of streak tube imaging system are discussed in this paper, and the corresponding mathematical analyses are also made to predict the performance, finally, basing on the theoretical design, we set up experiment to validate the range distinguishing ability of the system and get the practical resolution data. The feasibility of streak tube imaging system is also demonstrated through the theoretical analysis and experimental results.

Select this Article		Test of Russian K004M and K008 image converter cameras when recording trigger lightning in Florida V. B. Lebedev, G. G. Feldman, B. N. Gorin, V. A. Rakov, M. A. Yuman, and R. K. Olsen Proc. SPIE 6279, 62790D (2007); http://dx.doi.org/10.1117/12.725078 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract There has been presented a brief description of test equipment and instrumentation for recording spatial-time parameters of a lightning at the International Center for Lightning Research & Testing (ICLRT) in Camp Blanding that belongs to the University of Florida as well as the first results of Russian image converter cameras test when recording a trigger lightning.

Select this Article		Research of the streamer microwave discharge in a quasi-optical beam of electromagnetic wave with application of the K011 image converter camera Igor I. Esakov, Vladimir L. Bychkov, Grigory G. Feldman, Lev P. Grachev, Kirill V. Khodataev, and Vitaly B. Lebedev Proc. SPIE 6279, 62790E (2007); http://dx.doi.org/10.1117/12.725079 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Nowadays of microwave (MW) gas discharge applications are actively investigated in different areas of science and technology. Greatest optimism in applications is connected with streamer discharge forms. A possibility of streamer form discharge applications is determined by their specific features. An efficiency of energy absorption is close to 100% in this discharge. The discharge develops in a form of a spatial structure consisting of streamer element interconnected. They explode at reaching of electrodynamic resonance. The discharge structure represents a net of thin plasma channels. Gas temperature reaches several thousands of Kelvin degrees inside them. A typical time of energy absorption by separate plasma channels is several units of microseconds. A velocity of a streamer growth is about of - 106 cm/s. Main physical mechanisms determining features of MW discharges have been qualitatively clarified nowadays. But quantitative investigations of discharge creation processes are required for effective applications of these discharges. For this purpose equipment, which has characteristics allowing detecting processes with resolution time in microsecond and submicrosecond range, is necessary. In this work we represent investigation results of streamer MW discharge in air: initial development stage, developed stage of a volumetric discharge and development of the discharge on a surface of radiotransparent dielectric material. Investigations have been realized with a help of K011 image converter camera.

Select this Article		Optical trajectory diagnosis of 1.5MA wire-array Z pinches with fiber coupled streak camera Z. Wang, J. L. Yang, L. B. Li, R. K. Xu, and Z. H. Li Proc. SPIE 6279, 62790F (2007); http://dx.doi.org/10.1117/12.725080 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A fiber coupled streak camera is developed and applied in Z-pinch experiments to investigate the optical trajectory of wire-array implosions with one-dimensional (1D) spatial resolution of 100~400. The 1D image of the imploding plasma is formed by a slit and relayed to a linearly arranged fiber array, which is capable of transmitting the 1D image out from within the vacuum chamber. A mylar film is setup before the fiber array to absorb the X-ray light while transmitting visible light into the fibers, which are coupled to a streak camera. And for X-ray diagnosis the mylar film is substituted by an infra scinllator, which converts X-ray into visible light and relays it into the fiber array. The experiments were performed on QiangGuang-1 facility. With the slit parallel to the axis of the wire array, optical measurement of time-resolved radial distribution of the imploding plasma is carried out as well as diagnosis of X-ray implosion dynamics. The 1D optical trajectory (radius versus implosion time) of imploding plasma is obtained. And some discussions of the experiments are also presented in this letter.

Select this Article		Compact 8-way fast high voltage pulses generation with variable pulsewidth and interval time J. Liu, F. Zhang, L. Li, L. Niu, W. Peng, J. Shi, Q. Yang, and H. Niu Proc. SPIE 6279, 62790G (2007); http://dx.doi.org/10.1117/12.725081 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A programmable 8-way fast high voltage pulses generation built with avalanche transistors are studied. The fall time of raw pulse is 200 ps with amplitude about 2 kV. The fall time is determined by transit time of carries in collector-base region and it can be improved much by increasing the potential in this region. The pulse width can be switched programably with 1-ns, 2-ns and 5-ns. The pulses interval time also can be switched programably. The cover time range of 8-way pulses is more than 80-ns.

Select this Article		Application of image converter camera for investigation of discharges from an artificial cloud of charged water aerosol A. G. Temnikov, V. B. Lebedev, G. G. Feldman, L. L. Chernensky, A. V. Orlov, and V. P. Pisarev Proc. SPIE 6279, 62790H (2007); http://dx.doi.org/10.1117/12.725095 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Results of experimental investigations of optical characteristics of discharges from an artificial cloud of charged water aerosol by using the K011miniature 9-frame image converter camera are presented in the paper. Application of high speed image converter camera has allowed clearly distinguished the peculiarities of a final stage of three types of discharges from the charged aerosol clouds. Each type of final stage is differed not only on optical and current characteristics, but the sequence of formation. It was found that the type of final stage depends on character of development the previous leader discharges in the gap "charged aerosol cloud-grounded rod on the plate". The most frequently case is the formation of final stage after development of upward leader from the grounded rod and of counterpart negative downward leader from the charged aerosol cloud boundaries. Simultaneously registered current characteristics have shown significant correlation between optical and current characteristics of final stage of discharge. More powerful discharge luminosity the higher current amplitude and the shorter final stage of discharge.

Select this Article		High frame rate imaging systems developed in Northwest Institute of Nuclear Technology Binkang Li, Kuilu Wang, Mingan Guo, Linbo Ruan, Haibing Zhang, Shaohua Yang, Bing Feng, Fengrong Sun, and Yanli Chen Proc. SPIE 6279, 62790I (2007); http://dx.doi.org/10.1117/12.725096 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents high frame rate imaging systems developed in Northwest Institute of Nuclear Technology in recent years. Three types of imaging systems are included. The first type of system utilizes EG&G RETICON Photodiode Array (PDA) RA100A as the image sensor, which can work at up to 1000 frame per second (fps). Besides working continuously, the PDA system is also designed to switch to capture flash light event working mode. A specific time sequence is designed to satisfy this request. The camera image data can be transmitted to remote area by coaxial or optic fiber cable and then be stored. The second type of imaging system utilizes PHOTOBIT Complementary Metal Oxygen Semiconductor (CMOS) PB-MV13 as the image sensor, which has a high resolution of 1280 (H) ×1024 (V) pixels per frame. The CMOS system can operate at up to 500fps in full frame and 4000fps partially. The prototype scheme of the system is presented. The third type of imaging systems adopts charge coupled device (CCD) as the imagers. MINTRON MTV-1881EX, DALSA CA-D1 and CA-D6 camera head are used in the systems development. The features comparison of the RA100A, PB-MV13, and CA-D6 based systems are given in the end.

Select this Article		3D framing camera system based on sample cumulation method Yanbing Jiang, Huiming Yan, Xiuda Zhang, Long Wang, and Yan Li Proc. SPIE 6279, 62790J (2007); http://dx.doi.org/10.1117/12.725097 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel three-dimensional (3D) camera concept system could capture 3D image with thousands of pixels at range of several kilometer in real time was presented. The camera used a pulse laser to illuminate the scene, a solid-stat chargecouple device(CCD) sensor, and sample cumulation technology based on a gated binary image intensifier. The cumulation charges captured in CCD carried the information of range. The system was designed to have some significant advantages, such as low cost, simply schemes, high speed mainly limited to the speed of CCD frame capture. Potential applications include navigation of autonomous helicopter, large target identification, sensing and guidance, auto collision avoidance, robotic vision, atmospheric sensing and topography. In the paper, we discussed the fundamental principle and schemes of the 3D camera system based on sample cumulation and presented the feasible experiment result with a photo multiplier tube with binary character to simulate one pixel of the 3D camera system. Then we discussed the factors which influence the quality of 3D image according to the experiment result.

Select this Article		Design and first tests of miniature K010X soft x-ray streak and single-frame camera V. B. Lebedev, G. G. Feldman, A. F. Myasnikov, N. V. Chernyshev, I. I. Shubski, Jingru Liu, Lijun Wang, Yongsheng Zhang, Xueqin Zhao, Guoxin Zheng, and Weiwei Xiao Proc. SPIE 6279, 62790K (2007); http://dx.doi.org/10.1117/12.725098 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Description of a new K010X soft X-ray camera and the first results of it tests carried out in Russia and China are presented. In a streak mode the full sweep time for a 2 cm sweep route length on the image converter screen is from 2 ns up to 600 microseconds. In a single-frame mode the corresponding frame duration is from ~10 ns up to ~ 660 microseconds. Spatial resolution in a single frame mode was not less than 5 l.p./mm for soft X-ray radiation and not less 10 l.p./mm for UV radiation. Spatial resolution in a streak mode for soft X-ray radiation was from 5 up to 10 l.p./mm and for UV radiation on all the sweep ranges was not less than 10 l.p./mm, except for the range of 1 ns/cm where it was 5 l.p./mm. Limiting temporal resolution for UV radiation was near 10 ps and a dynamic range was 200 when full sweep time was 60 ns. The camera has small 430×115×200 mm dimensions, 5.0 kg weight and 10 VA power consumption.

back to top

Image Processing and Data Analysis

Select this Article		Computer modeling of shadowgraph optical setup Mingyu Sun Proc. SPIE 6279, 62790L (2007); http://dx.doi.org/10.1117/12.725100 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For high speed flows with a short duration of test time, one has to construct an optical system without having an image of it, which can be obtained only after running an experiment. In order to solve this problem, we propose a technique to simulate the shadowgraph method together with the flow field by computer in this paper, so that one can optimize the optical system on a computer before experiment. In the technique, the experiment is represented by the solution given by computational fluid dynamics (CFD), and the image is obtained by tracing rays through the numerical solution as well as the optical setup. The effects of optical components, such as the location of lens, the size of pinhole, the location of image plane, are analyzed. Having this technique, even a beginner can construct an optimized shadowgraph system at a negligible cost. The technique proposed can be used for analyzing schlieren system as well.

Select this Article		Computer analysis of the Schlieren optical setup Masayuki Anyoji and Mingyu Sun Proc. SPIE 6279, 62790M (2007); http://dx.doi.org/10.1117/12.725101 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In order to evaluate the influence of each component of the Schlieren optical setup, this work tries to simulate the whole setup by a computer, so that one can get an immediate computer image after adjusting the component. The analysis is based on the ray tracing method. All rays are traced from the light source to the recording plane, so that all components in the light path can be investigated. In our analysis, Schlieren optical setup is decomposed to two main modules, illuminating and recording optical setups. Each module contains typical optical arrangements that are commonly used. The numerical models devised for the optical arrangements are proposed, and a few results indicating the effect of the shape and the orientation of a cutoff are shown.

Select this Article		A robustness-enhancing method for real-time surface defection inspection Zhihua Dong, Zhijiang Zhang, and He Ma Proc. SPIE 6279, 62790N (2007); http://dx.doi.org/10.1117/12.725102 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Surface defection inspection methods based on machine vision have lots of advantages over many other automatic inspection methods, such as higher flexibility, lower overall cost, etc. However, the robustness of these methods is still unsatisfactory. Inspection of magnetic rings which are rich in texture and have various defections is a typical machinevision- based inspection task with high difficulty. Therefore, conclusions of the research on this problem are representative. In this paper, factors which lead to the variation of the inspection results are classified, and then a quantitative analysis for inspection systems introducing a new concept of robustness index is proposed. As an approach for enhancing robustness, the effect of the algorithm rule is focused on. The author extracts defection features on three levels in designing the rule and come to a conclusion that a complete extraction on higher level can enhance the robustness of the system after theory analysis and experiments.

Select this Article		Whole-field vibration analysis of a woofer's cone using a high-speed camera Qican Zhang, Xianyu Su, and Liqun Xiang Proc. SPIE 6279, 62790O (2007); http://dx.doi.org/10.1117/12.725103 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper we presented a method for whole-field three-dimensional (3D) shape measurement and vibration analysis of a vibrating woofer's cone based on Fourier transform profilometry (FTP). A sequence of dynamic deformed fringe images can be grabbed by high-speed CCD camera and saved on disk rapidly. By Fourier transform, filtering, inverse Fourier transform and unwrapping these phase maps in 3D phase space, we can obtain the shape of the rapid vibrating woofer's cone at different time. The results of our experiment indicate that the method, presented in this paper, can efficiently deal with the surface shape measurement for rapid motion object and will be a promising one with the development of high-speed frame grabber.

Select this Article		Rapid implementation of image processing onto FPGA using modular DSP C6201 VHDL model V. Brost, F. Yang, M. Paindavoine, and X. J. Liu Proc. SPIE 6279, 62790P (2007); http://dx.doi.org/10.1117/12.725104 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Recent FPGA chips, with their large capacity memory and reconfigurability potential, have opened new frontiers for rapid prototyping of embedded systems. With the advent of high density FPGAs it is now feasible to implement a high-performance VLIW processor core in an FPGA. We describe research results of enabling the DSP TMS320 C6201 model for real-time image processing applications, by exploiting FPGA technology. The goals are, firstly, to keep the flexibility of DSP in order to shorten the development cycle, and secondly, to use powerful available resources on FPGA to a maximum in order to increase real-time performance. We present a modular DSP C6201 VHDL model which contains only the bare minimum number of instruction sets, or modules, necessary for each target application. This allows an optimal implementation on the FPGA. Some common algorithms of image processing were created and validated on an FPGA VirtexII-2000 multimedia board using the proposed application development cycle. Our results demonstrate that an algorithm can easily be, in an optimal manner, specified and then automatically converted to VHDL language and implemented on an FPGA device with system level software.

Select this Article		Fluorescent image processing of image intensifier based on edge detector operator Youtang Gao, Benkang Chang, Yafeng Qiu, Si Tian, Jianliang Qiao, and Rongguo Fu Proc. SPIE 6279, 62790Q (2007); http://dx.doi.org/10.1117/12.725105 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The edge detector operator of image intensifier is a key problem for fluorescent image processing. This paper is intended to serve for three purposes: (1). To present the general problem of Fluorescent image in a sufficient depth and extent, (2) to present a complete algorithm for image processing including image sharpening and gradient operator. (3). to search for a edge detector optimal for fluorescent image processing of image intensifier. It is expected that a edge detector operator could provide a generic and robust solution to the reticle fluorescent noise images matching problem, which could be an important breakthrough in computer vision, photogrammetry, and pattern recognition.

Select this Article		Mosaics of images from architectural and heritage structures Ran Song and John E. Szymanski Proc. SPIE 6279, 62790R (2007); http://dx.doi.org/10.1117/12.725106 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents an automatic robust system which relies only on the information contained within the original images for the construction of massive composite mosaic images from close-range and high-resolution originals, such as those obtained when imaging architectural and heritage structures. We first apply the Harris Corner Detector to extract a selection of corners and, then, employ both the intensity correlation and the spatial correlation between the corresponding corners for matching them. We estimate the lens distortion parameter and the eight-parameter planar projective transformation matrix via the Levenberg-Marquardt algorithm. After the pairwise registration stage, we used a global optimization strategy, solving a linear system of equations to produce a globally consistent alignment of the entire set of original images. Lastly, image fusion using a weighted blending function together with intensity compensation produces an effective seamless mosaic image. Comparisons with current commercial image-mosaic software are favourable.

Select this Article		FFT-based 4-parameter global motion estimation Zhengbing Zhang, Zhenhua Xia, Xiaodong Xiong, and Guangxi Zhu Proc. SPIE 6279, 62790S (2007); http://dx.doi.org/10.1117/12.725107 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Motion estimation and compensation play important roles in video coding. The most commonly used motion estimation technique is block matching. In recent years, the global motion compensation (GMC) is paid great attentions because it is an important tool for a variety of video processing applications including for instance registration, segmentation and video coding. The phase correlation is a typical global motion estimation (GME) method in frequency domain. In this paper, a new 4-parameter GME method is proposed based on the Fourier transform properties of the tow images before and after global motion. At first, the scale and rotation parameters of the affine transform are estimated according to the formulas derived in this paper. Then the effect of scale and rotation of the affine transform are corrected with the estimated parameters. After that, the well-known phase correlation technique is used to determine the two shift parameters. An algorithm according to this principle is proposed in this paper, and simulation results show that the 4 affine parameters can be exactly estimated with our new method.

Select this Article		Noise reduction in electronic speckle pattern interferometry fringes by fourth-order partial differential equations Wei Lv, Chen Tang, and Wenping Wang Proc. SPIE 6279, 62790T (2007); http://dx.doi.org/10.1117/12.725109 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Noise reduction is one of the largest problems and biggest difficulties involved in electronic speckle pattern interferometry (ESPI). Although the second-order PDEs denoising method is a useful tool of noise reduction for the ESPI fringe patterns, its main drawback is that the second-order PDE model does not remove impulse noise, a 3×3 mean window filter is generally needed to improve the fringes. For overcome this main drawback, in this paper we apply the fourth-order PDE denoising model to the computer-simulated and experimentally obtained ESPI fringe, respectively. In both tests, the fourth-order PDE denoising model clearly outperforms the second-order PDE denoising model. Experimental results have confirmed that the fourth-order PDE denoising model is capable of removing noise in ESPI fringe images effectively.

Select this Article		A graduator test method based on dual dynamic image processing Zhebo Chen, Jin Xu, Xiangqun Cao, Bin Lin, and Zukang Lu Proc. SPIE 6279, 62790U (2007); http://dx.doi.org/10.1117/12.725110 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The graduator is a very important standard device in the optical angular measuring instrument, which determines the measure precision of the measuring instrument. A new graduator test method is discussed in this paper. This test method is a dual dynamic imaging measurement method with dual digital microscope system, which acquires the images of the graduator rotated by a rotating motor. Here is the introduction of this method with more detail. At first, fix a graduator to be measured on a rotary stage, this stage will be driven by a high precision programmable motor. Make the stage rotate with a constant angular velocity ω. Then place the digital microscope system upon the graduator. The digital microscope system includes two digital microscopes, which placed in the opposite diameter direction. Each digital microscope is made up of optical lens and a CMOS electro-ocular. The sampling frequency f can be set in the control software of the elector-ocular. The two digital microscopes make up a dual dynamic image acquire system. This system can acquire two images of the moving graduator at the same time with the sampling frequency f. Then, a serial of the graduator images can be acquired after a period of rotation, and there is a constant angular difference ω/f between every adjacent image. Each image of the graduator includes several graduation lines, identify these lines and get the position of the lines with image processing method. The measuring value of the rotate angle can be calculated from the adjacent line positions. Use the angular difference ω/f as a standard value of the rotate angle. Compare the measuring value and the standard value with the "comparing method of graduator measurement" formula. A compare result will be given to judge the graduator is good or not at last. The whole system is divided into four functional units: 1,the motion control unit;2,the dual dynamic imaging unit; 3, the image processing unit; 4,the data analysis unit. The measurement principle is introduced in the first part of the paper. In this part, the background of graduator measurement and the theories of graduator measurement are referred. According to the measurement principle a system design is made in the second part of the paper. In this part, the whole measure system is described: the structure of the system, the function of each component and the specifications for the key components. An experiment system is build up under the design, and some measurement data is obtained, the error analyses of the measure data is given at the last of the paper.

back to top

Femto-Attosecond Light and Photoelectron Sources

Select this Article		A femtosecond electron diffraction system Baosheng Zhao, Jie Zhang, Jinshou Tian, Junfeng Wang, Jianjun Wu, Yunquan Liu, and Hulin Liu Proc. SPIE 6279, 62790V (2007); http://dx.doi.org/10.1117/12.725112 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The femtosecond electron diffraction (FED) is a unique method for the study of the changes of complex molecular structures, and has been specifically applied in the investigations of transient-optics, opto-physics, crystallography, and other fields. The FED system designed by the present group, consists of a 35nm Ag photocathode evaporated on an ultraviolet glass, an anode with a 0.1mm aperture, two pairs of deflection plate for the deflection of electron beams in X and Y directions, and the Y deflection plate can be used as a scanning plate while measuring the pulse width of electron beams, the double MCPs detector for the enhancing and detecting of electron image. The magnetic lens was used for the focusing of the electron beams, and the focal length is 125mm. The distance between the object(the photocathode) and the image(the sample) is 503mm, and the size of electron beams is smaller than 17microns after focusing, the convergence angle is of -0.075~0.075°, and the temporal resolution is better than 350fs.

Select this Article		A potential method to control thermal distribution in a solid state heat capacity laser Yue Dong, Jifeng Zu, Liqun Hou, Zhigang Liu, Xianhua Yin, and Jianqiang Zhu Proc. SPIE 6279, 62790W (2007); http://dx.doi.org/10.1117/12.725150 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Approximate formulas of transient temperature and stress distributions in the slab of a two-sided pumped heat capacity laser (HCL) were attained by solving the heat diffusion equation. The thermal effects in the slab HCL were taken into consideration. By finite element analysis, the transient temperature and stress distributions in the slab medium were simulated with various boundary conditions, and the ANSYS simulations showed that when the pumping beam aperture was less than the pumping area, the peak thermal stress of the slab would increase to 80MPa. Then a new method for reducing thermal gradients between the outer surface of the slab and the internal portions in the slab was proposed, that was the temperature of the outer surfaces of the slab to be adjusted during the lasing stage for a HCL. This method is helpful to reduce the thermal peak stress to 40MPa. It not only provided a compensation for thermal gradients resulting from the limitation of the beam aperture during the pumping stage, but also further improved the output power and the beam quality. Our simulations are meaningful for designing a SSHCL especially the thermal management system in a SSHCL.

Select this Article		Temporal-spatial MTF performance analysis of a proximity-focused-image intensifier as a camera electronic shutter Shiming Xiang, Hongquan Zhu, and Kuilu Wang Proc. SPIE 6279, 62790X (2007); http://dx.doi.org/10.1117/12.725161 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A specially designed-Proximity-focused-MCP-Image Intensifier (MCP-II) has been widely used for a high speed diagnosis system as a ns-level-electronic shutter. Its temporal-spatial (dynamic) MTF or resolution are much concerned in the engineering for single exposure conditions of various shutter times, and input illuminations as well. On basis of the theory of Fourier spectrum and signal-to-noise, it has been analyzed in present paper that dynamic-MTF (or resolution) of the MCP-II system is always deteriorated by its limited temporal frequency bandwidth, as well as S/N performance. Several expressions are given to relate the device's dynamic MTF (or resolution) to its static MTF, input illumination and S/N performances. The theoretical analysis is very useful in evaluating and designing some high speed diagnosis systems with a proximity-focused-image intensifier as a electronic shutter.

Select this Article		Ultrafast microscopy of shock waves induced by femtosecond laser Li Huang, Yanqiang Yang, Yinghui Wang, Pengcheng Jin, Zhiren Zheng, and Wenhui Su Proc. SPIE 6279, 62790Y (2007); http://dx.doi.org/10.1117/12.725164 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Femtosecond-laser-induced shock waves in aluminum film deposited on alpha-quartz were generated at a repetition of up to ten shocks per second. Using ultrafast time-resolved microscopy of shock waves in different thickness of aluminum films, the shock velocity propagated in aluminum was measured to be 9.0±0.7 km/s. With shock wave equations of state, shock pressures in aluminum and -quartz were calculated to be 66(±15) GPa and 56(±15) GPa respectively, and final temperatures in aluminum and alpha-quartz were calculated to be 281 °C and 104 °C respectively.

back to top

Pulsed X-ray Sources and Radiography

Select this Article		New developments in flash radiography Arne Mattsson Proc. SPIE 6279, 62790Z (2007); http://dx.doi.org/10.1117/12.725167 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper will review some of the latest developments in flash radiography. A series of multi anode tubes has been developed. These are tubes with several x-ray sources within the same vacuum enclosure. The x-ray sources are closely spaced, to come as close as possible to a single source. The x-ray sources are sequentially pulsed, at times that can be independently chosen. Tubes for voltages in the range 150 - 500 kV, with up to eight x-ray sources, will be described. Combining a multi anode tube with an intensified CCD camera, will make it possible to generate short "x-ray movies". A new flash x-ray control system has been developed. The system is operated from a PC or Laptop. All parameters of a multi channel flash x-ray system can be remotely set and monitored. The system will automatically store important operation parameters.

Select this Article		High-speed hard x-ray phase-enhanced imaging Wah-Keat Lee, Kamel Fezzaa, and Jin Wang Proc. SPIE 6279, 627910 (2007); http://dx.doi.org/10.1117/12.725172 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Conventional x-ray imaging relies on the differences in the absorption of the sample to provide image contrast. With the small source sizes and large source-sample distances at synchrotrons, an additional mechanism, phase contrast, can come into play. Phase effects, which include refraction and diffraction, can greatly enhance the image contrast. Phase contrast is particularly useful in cases where the absorption contrast is weak. Added to this, the high x-ray flux available at synchrotrons allows for unprecedented high-speed and high-resolution x-ray imaging. We demonstrate that high quality time resolved images with sub-microsecond temporal and micrometer spatial resolutions are feasible. The range of energy spectrum (5-150 keV) available at the Advanced Photon Source allows us to study a wide range of samples, from soft tissues to high-Z materials. We will present preliminary results from the steel automobile fuel injectors and liquidair sprays

Select this Article		Enhanced k-edge angiography utilizing a superfluorescent x-ray generator with a gadolinium-target tube Eiichi Sato, Rudolf Germer, Haruo Obara, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Shigehiro Sato, and Kazuyoshi Takayama Proc. SPIE 6279, 627911 (2007); http://dx.doi.org/10.1117/12.725174 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The gadolinium plasma flash x-ray generator is useful for performing high-speed enhanced K-edge angiography using cone beams because K-series characteristic x-rays from the gadolinium target are absorbed effectively by iodine-based contrast media. In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash x-rays are produced by the discharging. The x-ray tube is a demountable cold-cathode diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current are approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic x-ray intensities of gadolinium increased. Bremsstrahlung x-ray intensity rate decreased with increasing the charging voltage, and clean K lines were produced with a charging voltage of 80 kV. The x-ray pulse widths were approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 500 Gy at 1.0 m from the x-ray source with a charging voltage of 80 kV. Angiography was performed using a filmless computed radiography (CR) system and iodine-based contrast media. In the angiography of nonliving animals, we observed fine blood vessels of approximately 100 m with high contrasts.

Select this Article		Conceptual design of a high-frame-rate fast neutron radiography detector Fa-qiang Zhang, Zheng-hong Li, Jian-lun Yang, Cun Guo, Hong-qiong Yang, Fan Ye, Zhen Wang, Chun-tong Ying, and Guang-jun Liu Proc. SPIE 6279, 627912 (2007); http://dx.doi.org/10.1117/12.725151 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Fast neutron radiography offers means to inspect thick hydrogenous materials because of high penetration depth of fast neutrons. Further more, quasi monoenergetic neutrons is relatively easy to obtain by neutron generators and it is helpful for density inversion of targets, which has many difficulties in flash radiography. In order to investigate dynamic processes, an intense repetitive pulsed neutron source will be used. Efficient detection of fast neutrons is one of the hardest problems for fast neutron imaging detectors. In the system, a scintillating fiber array is employed to obtain a detection efficiency of about 20% for DT neutrons. High-performance ICCDs and large aperture lens are taken into account to increase the conversion efficiency and the collective efficiency. The properties of the detector are charaterized in this paper.

Select this Article		Development of capillary Z-pinch discharge soft x-ray laser Yuanli Cheng, Qiushi Zhu, Yonpeng Zhao, Bohan Luan, Yang Li, Yao Xie, and Qi Wang Proc. SPIE 6279, 627913 (2007); http://dx.doi.org/10.1117/12.725160 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The work on lasing in Ne-like Ar at 46.9nm by using a Blumlein transmission line is reported. The discharge system consists of a Marx generator with maximum charging voltage of 300kV, a Blumlein transmission line and a pre-pulse circuit. Both results of theory and experiment illustrate that the inherent high-amplitude pre-pulse (~5kA) causes serious wall ablation, low homogeneity of plasma column and there would be no lasing. While the pre-pulse with an amplitude of ~20A greatly reduces ablation, engenders uniform plasma column, and provides necessary condition for lasing. The soft x-ray amplification in Ne-like Ar at 46.9nm has been achieved. The plasma columns are pumped by a 28~36kA current pulse with 80ns half-cycle duration in a 3.1mm-diameter and 12cm-length capillary channels filled with Ar gas. The full width at half-maximum of the laser spike is determined to be ~2ns and the output energy of the laser is estimated to be 3μJ.

Select this Article		A sort of pulsed microfocal x-ray source Kaige Wang, Baoping Guo, Jinchuan Guo, Ji Li, Qinlao Yang, Xiaomei Kuo, Junlan Zhou, and Hanben Niu Proc. SPIE 6279, 627914 (2007); http://dx.doi.org/10.1117/12.725163 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A sort of pulsed microfocus x-ray source has been theoretically and experimentally studied. The portable x-ray source is composed of three portions: LaB6 crystal cathode electron gun emitting system, electrostatic focusing system, and metal target system. The electrons are emitted form the hot crystal cathode, and controlled by modulated Wehnelt grid bias value and the ratio Dw/H, and concentrated by two-equal-radius-cylinder-electrodes focusing system. The x-ray photons are irradiated by high energy electron beam bombarding metal target. The new x-ray source's general-purpose capabilities such as pulsed radiation, focal spot size and luminance were preliminary tested. When the temperature of LaB6 cathode is about 1900K and partial pressures being kept below 10-7 torr, the minimal focus diameter is merely about 10 microns with the pulse width 65ms.

Select this Article		Design of remote control system for x-ray framing camera Li Li, Jinyuan Liu, Fengxia Zhang, and Wenda Peng Proc. SPIE 6279, 627915 (2007); http://dx.doi.org/10.1117/12.725165 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the implementation of a remote control system, where a PC and a single chip microprocessor are used in a dedicated application to remote control an X-ray framing camera. It can implement some programmable functions, such as driving pulse width adjustment, delay time adjustment between drivin8g pulses, MCP and phosphor screen bias voltage control. These parameters can be selected with the key board in front panel or with the host computer. A very simple communication link is presented using the ordinary communication protocol RS-232.

back to top

Diagnosis of High-Temperature and High-Density Plasmas

Select this Article		The application of high-speed photography in z-pinch high temperature plasma diagnostics Kui-lu Wang, Meng-tong Qiu, and Dong-wei Hei Proc. SPIE 6279, 627916 (2007); http://dx.doi.org/10.1117/12.725166 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This invited paper is presented to discuss the application of high speed photography in z-pinch high temperature plasma diagnostics in recent years in Northwest Institute of Nuclear Technology in concentrative mode. The developments and applications of soft x-ray framing camera, soft x-ray curved crystal spectrometer, optical framing camera, ultraviolet four-frame framing camera and ultraviolet-visible spectrometer are introduced.

Select this Article		Experimental modeling and high speed photographic studies of gas laser cutting of sheet metal P. V. Yudin, A. P. Petrov, and O. B. Kovalev Proc. SPIE 6279, 627917 (2007); http://dx.doi.org/10.1117/12.725170 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The study is intended to the investigation of melt removal process during gas laser cutting of sheet metal. Model setup, revealing visual access into the cutting kerf is developed. High speed photography technique is applied for the process recording. Explanation of the melt removal process is given. Interpretation is based on the model cutting shooting analysis and gas flow inside channel visualization data. Mechanisms of striated roughness generation are studied. Gas flow separation is discovered to be the reason for elevated roughness of the cutting surfaces at the lower part. Flow separation leads to vortex formation and reflux motion of the molten film, adjacent to the cutting front. Cutting regimes that are free of these phenomena are also considered. Adequacy of the model experiment to the real case is demonstrated.

Select this Article		Accuracy of two-color pyrometry using color high-speed cameras for measurement of luminous flames Hiroyuki Usui and Kenji Mitsui Proc. SPIE 6279, 627918 (2007); http://dx.doi.org/10.1117/12.725173 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract By the recent development in electronics, including new solid-state image sensors such as area CCD and C-MOS sensors and the progress of image processing techniques, new imaging radiometers have been developed which two-dimensionally acquire image data of objects moving at a high speed and under high temperature, and (graphically) present the temperature distribution over the object immediately. We successfully measured the temperature distribution and the term KL distribution, which is the absorption strength of combustion in diesel engine cylinders or other luminous flames taking place at a high speed, using single-sensor color high-speed cameras and applying two-color pyrometry introduced by H. C. Hottel and F. P. Btoughton. The measurement accuracy depends on the accuracy of color reproducibility of the high-speed camera being used which is considered a brightness pyrometer, because two-color pyrometry for measuring luminous flames is based on the brightness temperature at two wavelength bands such as red and green. In this paper, we present a method of maintaining the accuracy of measurement using a high-speed camera as a brightness pyrometer and of two-color pyrometry that was developed based on it.

Select this Article		A Mach-Zehnder nonzero order joint transform correlator based on the YIQ color space for polychromatic pattern recognition Chungcheng Lee, Chulung Chen, Kaining Gu, and Yanan Hou Proc. SPIE 6279, 627919 (2007); http://dx.doi.org/10.1117/12.725175 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel nonzero-order joint transform correlator system with the Mach-Zehnder configuration for polychromatic pattern recognition is presented. To remove zero order term is a very important thing for optical pattern recognition. We cleverly utilize the Stokes relations to remove the large zero order term directly in only one step in this structure. In the proposed technique, we investigate color pattern recognition with YIQ channels involving in-plane distortion such as rotations. Furthermore, the utilization of minimum average correlation energy to generate the composite reference image for enhancing the correlation output is also studied. The computer simulation results are presented to show the validity of the proposed technique.

back to top

Ultrafast Lasers and Applications

Select this Article		High power short pulse fiber lasers Guofu Chen, Wei Zhao, Yishan Wang, and Guanglei Ding Proc. SPIE 6279, 62791A (2007); http://dx.doi.org/10.1117/12.725177 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes characteristics of a short pulse doped rare earth fiber laser and amplifier. We have obtained very stable pico-second and femto-second laser pulses from fiber laser. An all-fiber laser and amplifier of a double-clad fiber are researched in detail. The pulse of 177fs at wavelength of ~1.50um has been got from fiber laser. The energy of single pulse of 153J has been obtained after an amplifier of a double-clad fiber at repetition-rate of 30 KHz.

Select this Article		Continuous-wave supercontinuum generation in a 100-m high nonlinear photonic crystal fiber Yongqin Yu, Shuangchen Ruan, Jihong Zhao, and Chenlin Du Proc. SPIE 6279, 62791B (2007); http://dx.doi.org/10.1117/12.725181 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract To our best knowledge, the most supercontinuum sources generated by use of cw pump lasers were obtained with fiber interaction lengths of the order of 100 m to a few kilometers to enhance the optical nonlinearity. However, the material loss was accumulated and the price cost was boosted in the long fibers. In this paper, CW supercontinuum generation by use of a 1480-nm fiber-Raman laser (FRL) in a 100-m high-nonlinear photonic crystal fiber (PCF) together with a 76-km single mode fiber (SMF) was demonstrated. The broadband supercontinuum was obtained with 10-dB bandwidth of 124 nm spanning from 1476 to 1600 nm. It was shown that the principal mechanism of the broadening could be assigned to stimulated Raman scattering, four-wave mixing (FWM) and modulation instability (MI).

Select this Article		Double-end-pumped acoustic-optically q-switched intracavity-frequency-doubling red laser Wan Qin, Chenlin Du, Shuangchen Ruan, and Yuncai Wang Proc. SPIE 6279, 62791C (2007); http://dx.doi.org/10.1117/12.725183 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We report a high-power diode-double-end-pumped Q-switched Nd:YVO₄ red laser through intracavity frequency-doubling with a type-I critical phase-matched LBO crystal. At the repetition frequency of 26 kHz, the maximum quasi-continuous-wave (QCW) output power at 671 nm was measured to be 9.2 W at the incident pump power of 62.4 W with the corresponding optical conversion efficiency of 14.7%; the pulse width of about 106 ns; the pulse energy of 353.8J; the peak power of 3.34 kW, respectively. The perfect performance indicated that the double-end-pumped technique could effectively diminish the thermal lens effect, extend the range of the stable resonator region and achieve a high optical conversion efficiency to obtain a high output power.

back to top

High-Speed Holography and Interferometer

Select this Article		Novel imaging interferometer for upper high-speed atmospheric wind field survey ChunMin Zhang, BaoChang Zhao, YingCai Li, and JianYong Ye Proc. SPIE 6279, 62791D (2007); http://dx.doi.org/10.1117/12.725184 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A Novel Imaging Interferometer (NII) based on modified Michelson interferometer for surveying the physical properties of upper high speed atmospheric wind filed is presented. Taking the natural airglow and auroral visible emission lines in the upper atmosphere as surveyed source, NII can be used to retrieve the velocity and temperature of the upper high speed atmospheric wind field through the interference imaging spectroscopy coupled with the Doppler effect of electromagnetic wave. The optics system, survey principle, model and surveying method of four intensities are described. Simulated experimental of velocity and temperature of wind field is shown. NII has the advantages of wide field of view, bigger OPD, high resolution, achromatic, thermally stable, and is suitable for measuring upper atmospheric wind field.

Select this Article		Ultra-fast digital holography of the femto-second order Hongchen Zhai, Xiaolei Wang, and Guoguang Mu Proc. SPIE 6279, 62791E (2007); http://dx.doi.org/10.1117/12.725176 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We report on pulsed digital micro holographic systems recording ultra-fast process of the femto-second order, by spatially angular division multiplexing (SADM) and wavelength division multiplexing (WDM), respectively. Both intensity and phase images of the digitally reconstructed images are obtained through Fourier transformation and digital filtering, which show clearly the plasma forming and propagating dynamic process of laser induced ionization of ambient air at the wavelength of 800 nm, with a time resolution of 50 fs and frame intervals of 300 to 550 fs.

Select this Article		A high-speed high-responsive PMT-based detector Yuri V. Shcherbakov and Gennadij D. Domashenko Proc. SPIE 6279, 62791F (2007); http://dx.doi.org/10.1117/12.725178 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A coupled pair of high-speed photomultiplier tube (PMT) based detector in series with the ultra-broadband amplifier has been presented here. This combined device is intended for accurate measurements of high-speed low-luminous processes in various fields of investigations. Their practical applications and parameters have been illustrated in many details. Successful application of the device to studying the short gap streamer corona discharge in very fast transient stage of primary streamer propagation has been illustrated. The device is able to be a very competitive product as compared to new generation of the PMT-based detectors produced by the Hamamatsu Company who is the world leader in this field.

Select this Article		Optimization of the modified Sagnac imaging interferometer for full compensation Yuanhe Tang, Guangde Chen, Chunmin Zhang, Yunlong Lin, Hanchen Liu, and Kai Liu Proc. SPIE 6279, 62791G (2007); http://dx.doi.org/10.1117/12.725182 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The modified super-wide-angle Sagnac interferometer (SASI) is designed for upper atmospheric wind measurement. The formula of SASI's optical path difference (OPD) is derived, in which the OPD versus the sine series of incidence angle in order of 4. The SASI's fully compensations of super-wide-angle, achromatic, thermal, wavelength-independent thermal conditions have been investigated. The SASI configuration for the above compensations was successfully setup by selecting correct glasses from the 113 kinds of glasses. The optimized SASI is made of ZBaF17 and QF14 glasses, and the arm lengths are accurately configured. Based on the configuration of glass types and arm lengths of SASI, it shows that SASI achromatic condition is satisfied synchronously for three aurora's emission lines, which are 557.7nm, 630.0nm and 732.0nm respectively. The relative error of SASI's lengths does not exceed 1%. The full field of view (FOV) of the SASI is 6°. It is about 5° in full angle from SASI optical axis to CCD farthest corner. The first order fringe occupies about 67% of the CCD area.

Select this Article		Photochromic diarylethene for holographic optical recording Shouzhi Pu, Baoli Yao, Tianshe Yang, Jingkun Xu, Yingli Wang, and Ming Lei Proc. SPIE 6279, 62791H (2007); http://dx.doi.org/10.1117/12.725186 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A unsymmetrical photochromic diarylethene, 1-(2-methyl-5-phenylthien-3-yl)-2-[2-methyl-5-(3-fluorophenyl)thien- 3- yl]perfluorocyclopentene (1a), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. The compound showed good photochromism in solution, in PMMA amorphous film and in the singlecrystalline phase upon photo-irradiation. Using the diarylethene 1b/PMMA film as recording medium and a nonpolarized He-Ne laser (633 nm, 4 mW) for recording and readout, three types of polarization holographic optical recording were carried out successfully. The results showed that different patterns can be displayed with differently polarized readout lights, which can be applied in camouflage technology.

Select this Article		Optical fiber current sensor based on Bi₄Ge₃O₁₂ crystal with enhanced Faraday rotation by critical angle reflections Meirong Wang, Wangmin Zhou, Peng Zhang, Jianlin Zhao, Hao Zhang, and Peifeng Wei Proc. SPIE 6279, 62791I (2007); http://dx.doi.org/10.1117/12.725185 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The feasibility of utilizing Bi₄Gi₃O₁₂ (BGO) crystals as sensing element for optical fiber current sensors (OCSs) with enhanced sensitivity is demonstrated. Based on the theoretical analyses of the magneto-optical properties of BGO crystal, the Verdet constants of the crystal at different wavelengths are measured by employing the double frequency method. By combining the measured absorption coefficients with the relations between the Verdet constants and wavelengths, the magneto-optical figure of merit of BGO crystal is obtained. After that an OCS based on a BGO crystal with a magnetic field concentrator and enhanced Faraday rotation by critical angle reflections is designed and experimentally demonstrated. Finally, the influences of the phase shift caused by reflection, which is the main resource of the deviation between the measured and the real values, are theoretically analyzed and numerically simulated. It is demonstrated that an OCS based on BGO crystals with enhanced Faraday rotation could be developed into a practical OCS with a good linearity and a large dynamic range.

Select this Article		Recording conditions of digital holography Huaying Wang, Dayong Wang, Jianjun Xie, and Shiquan Tao Proc. SPIE 6279, 62791J (2007); http://dx.doi.org/10.1117/12.725187 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Based on Fresnel diffraction formula, the spatial frequency distribution of the holograms recorded with plane and spherical reference wave are analyzed. Using the sampling theorem and the condition of spectrum separation, the general recording conditions of the digital hologram are deduced. The minimum recording distances and the offsets of the reference wave for some practical recording configurations are given. The deduced recording conditions about off-axis Fresnel hologram are different from others, which are different each other. The separating condition of the frequency spectrum for Fourier transform holography is applied directly in their derivation. Moreover, they have applied different other approximations in their derivation. No approximation is applied to our deduction. Therefore, the results derived from our proposed method are accurate. The recording conditions of digital holography with general spherical reference wave are presented firstly on our knowledge. The recording conditions of in-line and off-axis lensless Fourier can be gotten directly as special case. The simulations and the experiments demonstrate that the method and the results are valid. The results also show that only the sampling and separation conditions are met simultaneously, the reconstructed image with high quality can be obtained.

back to top

High-Speed Video Technique

Select this Article		Lincoln Laboratory high-speed solid-state imager technology R. K. Reich, D. D. Rathman, D. M. O'Mara, D. J. Young, A. H. Loomis, R. M. Osgood, R. A. Murphy, M. Rose, R. Berger, B. M. Tyrrell, S. A. Watson, M. D. Ulibarri, T. Perry, F. Weber, and H. Robey Proc. SPIE 6279, 62791K (2007); http://dx.doi.org/10.1117/12.725189 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Massachusetts Institute of Technology, Lincoln Laboratory (MIT LL) has been developing both continuous and burst solid-state focal-plane-array technology for a variety of high-speed imaging applications. For continuous imaging, a 128 × 128-pixel charge coupled device (CCD) has been fabricated with multiple output ports for operating rates greater than 10,000 frames per second with readout noise of less than 10 e- rms. An electronic shutter has been integrated into the pixels of the back-illuminated (BI) CCD imagers that give snapshot exposure times of less than 10 ns. For burst imaging, a 5 cm × 5 cm, 512 × 512-element, multi-frame CCD imager that collects four sequential image frames at megahertz rates has been developed for the Los Alamos National Laboratory Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. To operate at fast frame rates with high sensitivity, the imager uses the same electronic shutter technology as the continuously framing 128 × 128 CCD imager. The design concept and test results are described for the burst-frame-rate imager. Also discussed is an evolving solid-state imager technology that has interesting characteristics for creating large-format x-ray detectors with ultra-short exposure times (100 to 300 ps). The detector will consist of CMOS readouts for high speed sampling (tens of picoseconds transistor switching times) that are bump bonded to deep-depletion silicon photodiodes. A 64 × 64-pixel CMOS test chip has been designed, fabricated and characterized to investigate the feasibility of making large-format detectors with short, simultaneous exposure times.

Select this Article		Ultrahigh-speed, high-sensitivity color camera with 300,000-pixel single CCD K. Kitamura, T. Arai, J. Yonai, T. Hayashida, H. Ohtake, T. Kurita, K. Tanioka, H. Maruyama, J. Namiki, T. Yanagi, T. Yoshida, H. van Kuijk, Jan T. Bosiers, and T. G. Etoh Proc. SPIE 6279, 62791L (2007); http://dx.doi.org/10.1117/12.725213 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We have developed an ultrahigh-speed, high-sensitivity portable color camera with a new 300,000-pixel single CCD. The 300,000-pixel CCD, which has four times the number of pixels of our initial model, was developed by seamlessly joining two 150,000-pixel CCDs. A green-red-green-blue (GRGB) Bayer filter is used to realize a color camera with the single-chip CCD. The camera is capable of ultrahigh-speed video recording at up to 1,000,000 frames/sec, and small enough to be handheld. We also developed a technology for dividing the CCD output signal to enable parallel, highspeed readout and recording in external memory; this makes possible long, continuous shots up to 1,000 frames/second. As a result of an experiment, video footage was imaged at an athletics meet. Because of high-speed shooting, even detailed movements of athletes' muscles were captured. This camera can capture clear slow-motion videos, so it enables previously impossible live footage to be imaged for various TV broadcasting programs.

Select this Article		Design and implementation of high-speed CCD driving circuit based on CPLD L. Zhang, Y. X. Li, X. J. Li, and X. W. Xu Proc. SPIE 6279, 62791M (2007); http://dx.doi.org/10.1117/12.725215 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In CCD detecting system of dynamic target, the design of high speed CCD driving circuit is a key technique in its application. This paper, taking CCD IL-P3 produced by DALSA Company recently for example, according to the demands of CCD driving timing, introduces a designing method of high speed CCD driving circuit. A CPLD device of ALTERA Company's MAX7000S series is chosen as a hardware carrier to design the driving timing generator with adjustable exposure time. After compiled and simulated in MAX+PLUSII, the program is fitted into the CPLD device by using JTAG interface. And experimental results show that the expected CCD driving plus signals can be get.

Select this Article		The optimized method of video coding rate control based on rate distortion Xiaohui Li and Li Wang Proc. SPIE 6279, 62791N (2007); http://dx.doi.org/10.1117/12.725217 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A method of video coding rate control by joint picture-layer and macroblock-layer is proposed in this paper. In picturelayer, the number of bits in each frame is pre-allocated on the whole, and a reference quantization parameter is determined. Then, according to rate-distortion principle, when each frame is encoded, the optimized quantization parameter is selected for intra-frame different macroblocks with the minimal distortion. The result of simulation shows that the proposed method of video coding rate control can reduce or avoid buffer from overflow or underflow efficiently, stabilify the output bit-steam and improve the peak signal-noise-ratio (PSNR) of re-constructed video signal.

Select this Article		High speed deformation measurement using digital speckle correlation method Hua Chen, Dong Ye, and Rensheng Che Proc. SPIE 6279, 62791O (2007); http://dx.doi.org/10.1117/12.725219 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This article discusses an advanced deformation method based on digital speckle correlation method, which is substantially more robust and has greater dynamic range than other full-field imaging technologies such as ESPI and moir. The system tracks the stochastic pattern applied to the measurement surface with sub-pixel accuracy. The object under test is viewed by a pair of high resolution, digital CCD cameras. Two cameras having been mounted the locations and attitudes were calibrated prior to measurement by combining nonlinear optimization with accurate calibration points. The calibration points were formed by an infrared LED, which moved with 3-D coordinate measurement machine. By using bilinear interpolation square-gray weighted centroid location algorithm, the imaging centers of the calibration points can be accurate. The speckle images of the same measured zone from different directions for the specimen are recorded by two cameras before and after deformation. Then the deformation displacement and strain of the specimen is calculated by these images using digital speckle correlation method and geometrical relation of stereography. The performance was demonstrated with real translation test.

back to top

Trajectory, Impact, and Explosion

Select this Article		Drift magnitude surveying in launching and taking-off processes of a large means of delivery Jingzhen Li, Rensheng Xiong, Hushun Wang, and Xiangdong Gong Proc. SPIE 6279, 62791P (2007); http://dx.doi.org/10.1117/12.725221 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper deals with the approaching surveying principle and data processing for launching and taking-off of a large means of delivery; moreover, the special requirements of the drift magnitude surveying optical system, the intermittent performance of the synchronous high speed camera, the high speed tracing and accurate measurement of angles, and the synchronous controlling, are also described. The approching survey means here the surveying range from the surveying facility to the launching tower is about 100m~200m.

Select this Article		Observations of impact phenomena of spherical projectile on aggregated particles in random packing Masahiro Nishida, Koichi Tanaka, and Yusuke Ikeda Proc. SPIE 6279, 62791Q (2007); http://dx.doi.org/10.1117/12.725222 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The dynamic behavior of aggregated spherical particles subjected to the impact of a steel spherical projectile was simultaneously recorded using two high-speed video cameras at different angles. The post-impact effects of a steel projectile with an impact velocity of 1-20 m/s and an impact angle of 0-65° on the dynamic behavior of aggregated particles were examined. The movement of the projectile after impact can be classified into four different types. In addition, the effects of the particle's diameter of aggregated particles and the depth of the container on the four different types of the projectile's movement were also examined. The use of small particles resulted in clear boundaries demarcating between the penetration and the horizontal movement or the rebound of the projectile.

Select this Article		The application of the high-speed photography in the experiments of boiling liquid expanding vapor explosions Sining Chen, Jinhua Sun, and Dongliang Chen Proc. SPIE 6279, 62791R (2007); http://dx.doi.org/10.1117/12.725224 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The liquefied-petroleum gas tank in some failure situations may release its contents, and then a series of hazards with different degrees of severity may occur. The most dangerous accident is the boiling liquid expanding vapor explosion (BLEVE). In this paper, a small-scale experiment was established to experimentally investigate the possible processes that could lead to a BLEVE. As there is some danger in using LPG in the experiments, water was used as the test fluid. The change of pressure and temperature was measured during the experiment. The ejection of the vapor and the sequent two-phase flow were recorded by a high-speed video camera. It was observed that two pressure peaks result after the pressure is released. The vapor was first ejected at a high speed; there was a sudden pressure drop which made the liquid superheated. The superheated liquid then boiled violently causing the liquid contents to swell, and also, the vapor pressure in the tank increased rapidly. The second pressure peak was possibly due to the swell of this two-phase flow which was likely to violently impact the wall of the tank with high speed. The whole evolution of the two-phase flow was recorded through photos captured by the high-speed video camera, and the "two step" BLEVE process was confirmed.

back to top

Diagnosis of Ultrafast Phenomena

Select this Article		Photoelectron time-resolved spectra of silver halide micro-crystal adsorbing green-sensitizing dye J-aggregates Fenghua Xiang and Jixian Zhang Proc. SPIE 6279, 62791S (2007); http://dx.doi.org/10.1117/12.725227 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Microwave absorption and dielectric spectrum detection technology, with high time resolution (less than 1ns), was used for non-contact measurement of electron property in solid materials. In this paper, the photoelectron decay time-resolved spectrums of silver halide, which adsorbed the green-sensitive cyanine dyes J-aggregate, are measured by microwave absorption and dielectric spectrum detection technology. From the experiment, we find that the photoelectron decay time and the photoelectron lifetime of silver halide, which adsorbed the dye, is shorter than that of the pure silver halide; the photoelectron decay time of silver bromide is faster than the photoelectron decay time of silver chloride, the free photoelectron lifetime of silver chloride and silver bromide is 51.66ns and 13.84ns respectively; the variety extent of silver bromide is bigger than that of the silver chloride after sensitized. The effect of the dye concentration on photoelectron decay of silver halide is obvious, for silver bromide and silver chloride, the photoelectron decay become faster while the concentration increases.

Select this Article		An experimental system using pulsed laser developed for detecting underwater objects Jionghui Rao, Kecheng Yang, Gang Lu, and Xiaohui Zhang Proc. SPIE 6279, 62791T (2007); http://dx.doi.org/10.1117/12.725228 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The influence of water backscattering on detecting ability should be considered emphatically when optical methods were used to detect underwater object. The water backscattering light can be decreased by using a short pulsed laser in the system and the precise distance of the detected object can be obtained easily. An experimental system made up of short pulsed laser, received optical system, narrowband light filter, high speed detector, high speed data acquisition and process system and so on was established. To validate its detection ability, this system was set into a large water pond to detect several kinds of objects with different reflection index. We processed mass of experimental data get from above experiment with simple method, and the processing result proved that this system had the ability of detecting objects whose distance is about sixty meters. Because of its precise ranging ability, this system can be used with the combination of a right scan device in three dimensional underwater imaging system.

back to top

Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)

Select this Article		Solid state replacement of rotating mirror cameras Alan M. Frank and Joseph M. Bartolick Proc. SPIE 6279, 62791U (2007); http://dx.doi.org/10.1117/12.725230 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Rotating mirror cameras have been the mainstay of mega-frame per second imaging for decades. There is still no electronic camera that can match a film based rotary mirror camera for the combination of frame count, speed, resolution and dynamic range. The rotary mirror cameras are predominantly used in the range of 0.1 to 100 micro-seconds per frame, for 25 to more than a hundred frames. Electron tube gated cameras dominate the sub microsecond regime but are frame count limited. Video cameras are pushing into the microsecond regime but are resolution limited by the high data rates. An all solid state architecture, dubbed 'In-situ Storage Image Sensor' or 'ISIS', by Prof. Goji Etoh has made its first appearance into the market and its evaluation is discussed. Recent work at Lawrence Livermore National Laboratory has concentrated both on evaluation of the presently available technologies and exploring the capabilities of the ISIS architecture. It is clear though there is presently no single chip camera that can simultaneously match the rotary mirror cameras, the ISIS architecture has the potential to approach their performance.

Select this Article		111-mega pixel high-speed, high-resolution CCD Kasey Boggs, Richard Bredthauer, and Greg Bredthauer Proc. SPIE 6279, 62791V (2007); http://dx.doi.org/10.1117/12.725231 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A 111-Mega pixel, 92x92 mm², full-frame CCD imager with 9x9 um² pixel size has been developed for use in scientific applications. Recent interest for ultra-high resolution imagers for electronic imaging OEM customers in various scientific markets, including biotechnology, microscopy, crystallography, astronomy, spectroscopy, and digital photography markets has lead to the development of the STA1600A 111-Mega pixel monochromatic charge-coupled device. Innovative design techniques were utilized in the early development of this device, yielding low RMS noise and high MTF for readout speeds ranging from 1 Mpixel/s to 10 Mpixel/sec. This paper will provide detailed information on the design and performance capabilities of the STA1600A, as well as background information on the commercial uses of this device.

Select this Article		A CMOS current-to-voltage linear conversion for low-input current, low noise and low power Bingliang Hu and Simon X. Yang Proc. SPIE 6279, 62791W (2007); http://dx.doi.org/10.1117/12.725234 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a very simple circuit of balanced two-stage current amplifier and regulated cascode (RGC) amplifier to realize a linear current-to-voltage conversion. It can accept very low currents in the nA range. The noise model and strategies for noise reduction are discussed. The circuit is designed for 0.18m CMOS technology and verified by simulations.

back to top

Shock Wave and Hypersonic Physics

Select this Article		Visual determination of the onset of irregular blast wave reflection H. Kleine, K. Hiraki, E. Timofeev, K. Ohashi, H. Maruyama, T. Hayashida, Y. Jun, K. Kitamura, T. Nakajima, A. Gojani, K. Takayama, and T. G. Etoh Proc. SPIE 6279, 62791X (2007); http://dx.doi.org/10.1117/12.725254 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents further results of an ongoing experimental and numerical investigation into the unsteady process of blast wave reflection from straight smooth surfaces. It is shown that basic blast wave phenomena such as the transition from regular to irregular wave reflection can be adequately and conveniently studied in a laboratory environment by using small charges with masses in the milligram range. While the laboratory scale generally provides greater accessibility, it also imposes more stringent conditions on the diagnostics than the large-scale environment. The paper reviews the previously found considerable discrepancies between numerical and experimental results for the location x_tr of the transition from regular to irregular wave reflection. These are caused by the initially minuscule size and gradual growth of the Mach stem and the limited resolution of the recording material. Different techniques are used to improve the accuracy of the experimental determination of the transition point, and a new combination of modern high-speed photography with the traditional soot technique is shown to be the most promising tool for this purpose.

Select this Article		Dynamic pressure measurement of shock waves in explosives by means of a fiber Bragg grating sensor P. G. van 't Hof, L. K. Cheng, J. H. G. Scholtes, and W. C. Prinse Proc. SPIE 6279, 62791Y (2007); http://dx.doi.org/10.1117/12.725258 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new technique for the dynamic measurement of detonation pressures by use of a Fibre Bragg Grating (FBG) sensor is reported. A variation in pressure changes the wavelength of the FBG reflected light. In a detonation, the shock wave passes the explosive with a velocity of ca. 7 km/s and the pressure builds up to ca. 20 GPa within 100 ns, so huge differences in pressure exist in a small area. To prevent measuring the average pressure in a few mm, short FBG with a length of about 0.5mm is developed by Hongkong PolyU and is inserted in the explosive. The light reflected by the FBG is sent to a fibre optic Mach-Zehnder interferometer with a 3x3 beam combiner. Pressure induced wavelength shift will cause a phase change of the interferometric signal. Using the 3 output signals of the interferometer, the phase can be calculated. Interaction between the FBG and the ionization light generated by the shockwave is also demonstrated.

Select this Article		Research on method of measuring the time of remote explosion point Jianmin Zhou, Hongyan Yin, Kai Xu, and Youyu Fu Proc. SPIE 6279, 62791Z (2007); http://dx.doi.org/10.1117/12.725261 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The time when the bomb explodes is one of the most important indexes to appraise the test. According to the principles concerned with explosion radiation, the principle of measuring the time of remote explosion point and composition of measuring system is introduced. Use CCD to record the explosion radiation, DSP to process and record the highcapacity, high-speed video signals, and convert the exploding process examined by floating amplifier into digital signals. Besides, the article analyzes the composing and structural design of the log's optical system, principle of electric control and floating amplifier, dynamic range of the system, power analysis of the incident light, and how to improve the accuracy of measurement in great detail.

back to top

Photonics

Select this Article		Photon emitting, absorption, and reconstruction of photons Changjun Liao, Jindong Wang, Zhengjun Wei, and Jianping Guo Proc. SPIE 6279, 627920 (2007); http://dx.doi.org/10.1117/12.725263 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Photon cannot keep itself unchanged from emission to absorption. The information encoded on the photon is also changed due to interaction with environment. There has no definitely demonstration that the photon being absorbed is the original one from ideal light source since the quantum mechanics itself is an indeterminate theory that the physical measurement is only the probability. We divide the change of the photon state into two parts that one can be compensated and the other cannot be compensated. A concept of photon reconstruction is introduced to explain every optical phenomena including Raman scattering, multi-photon absorption, nonlinear phenomena, free electron lasing, quantum entanglement, high order coherence, ghost imaging and the de-phase which result in error bits or information loss in the quantum information process. An experimental result is explained to show that the signal photon can modify the background even the energy of the photon is not enough for absorption in the wide-band gap semiconductor material. The photon-current-voltage curve and dark-current-voltage curve of an absorption, grating, and multiplication InGaAs/InP avalanche photodiode is analyzed to show that 1550nm input light modified the dark background even the applied reverse bias voltage is far below the punch-through voltage. This increase of the dark count directly relates to the input photons at the 1550nm wavelength but is not due to absorption in the absorption layer and insensitive to the applied voltage.

Select this Article		Research on the new performance model for LLL TV imaging systems Kecong Ai, Liwei Zhou, Guilin Zeng, Yanxi Liang, Chen Wang, and Xudong Li Proc. SPIE 6279, 627921 (2007); http://dx.doi.org/10.1117/12.725265 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Starting from threshold characteristics and night visual theory of the human eye the new quanta detector and linear filter integrated performance model, universal threshold detecting theory and synthesis detecting equations for LLL (low light level) TV imaging systems have been put foreword and established, which set up together active regularity and connection between photon noise fluctuation theory and linear filter theory. By using the new performance model and apparent distance detecting equations many specific properties of LLL TV imaging system, such as brightness intensified, visual angle enlarged, signal to noise ratio and contrast transferred and attenuated, can be correctly expressed, calculated and evaluated. The characteristics of the human eye can also be correctly reflected and described.

Select this Article		The dynamics of cavitation bubble clouds in high-intensity focused ultrasound field observed by high-speed photography Xiaojing Li, Hong Chen, and Mingxi Wan Proc. SPIE 6279, 627922 (2007); http://dx.doi.org/10.1117/12.725266 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High-speed photography is being considered as an effective technique to record the transient phenomena in medical field. This presentation summarizes our previous work of using high-speed photography in the observation of cavitation bubble clouds generated in high-intensity focused ultrasound (HIFU) field, aiming at the better understanding of the cavitation mechanism during the medical application of HIFU. A high-speed photography system synchronized with HIFU emission facilities was built up, and using this system we have investigated the dynamics of cavitation bubble clouds (i) in the whole HIFU free field; (ii) in the focal region of HIFU free field; and (iii) near the tissue surface in HIFU field. The spatial-temporal evolution of the bubble cloud and the characteristics of bubble cloud structures as well as the possible explanations to the recorded phenomena are reviewed. All the results we got elucidated that the highspeed camera is a potent tool to detect the cavitation phenomena in HIFU field.

Select this Article		Soliton self-trapping generation by femtosecond pulse in the highly birefringent photonic crystal fiber Jing Wang and Yan-mei Shi Proc. SPIE 6279, 627923 (2007); http://dx.doi.org/10.1117/12.725267 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Firstly, the possibility of yielding soliton self-trapping in the photonic crystal fiber (PCF) is analyzed, and it is found that, due to the high modal birefringence of PCF, the femtosecond-order initial pulse must be considered in order to realize the soliton self-trapping, so the effects of higher-order nonlinearity and higher-order dispersion need to be taken into account. Secondly, based on the coupled nonlinear Schrodinger equations, the influences of higher-order nonlinear and dispersive effects on the threshold value and the quality of soliton self-trapping are studied in detail with the slip-step Fourier method. The numerical results show that, the higher-order nonlinearity doesn't affect the threshold value but induces both the attenuation and red shift of the two polarized components, and the higher-order dispersion not only influence the pulse shape and width of two polarized components, but also change the threshold value under appropriate conditions. In conclusion, the PCF can also yield the soliton self-trapping with the interactions of all effects above.

Select this Article		Application of diazonaphthoquinone/novolak photosensitive material for photography image formation Ping Linda Zhang, Hai Liang Yu, Song Hu, Zhong Yuan Jin, Le Wang, Lu Chuan Zhang, and Yong Yang Proc. SPIE 6279, 627924 (2007); http://dx.doi.org/10.1117/12.725214 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Historically diazoquinone/novolak- the two-component photosensitive material (photoresist) was efficiently used in various industries. In the semiconductor industry it is used for the high contrast, high resolution binary image formation for the integrated circuitry. Comparing with the silver halide photosensitive system which has Ag₄ + cluster or T-grain sensitizing center that generates detailed gray scale (photographic density) black & white images, the diazoquinone / novolak resist for the gray scale image formation has not been investigated thoroughly in the past. Diazoquinone/novolak could be used in the photography field as one of the non-silver photosensitive materials and this passive photosensitive material also has its broad exposure-energy response towards the image formation. Here in this paper we provide this silver-halide supplement material to transfer our semiconductor photolithography binary process experience of that resist to its photography application. We also reported the TEM figures and the measurement data of the resist particle diameter after the photolithography development process. The thick photoresist was coated on the aluminum substrate. Using critical dimension, CD = 2m photomask to process several lots of wafers, the resist particles were collected and the particle size and its distribution after the development process was obtained. Their size distribution mainly has dual separate distribution peaks: 85% of particles have the diameter distributed around 23±3 nm and the rest 15% of bigger particles around 220±50 nm. Here in the experiment we use the standard-equivalent projection reticle to substitute the standard contact mask to obtain 2m CD latent images thereafter the corresponding particles throughout several lots. Because of the unique role of DNQ, which is both the photo-sensitizer and the development inhibitor before its exposure, the correlation of the resist particle size with respect to the developer concentration, the size of the radius of gyration, the "photosensitizing center" and the "development center" is speculated. Generally the particle size distribution is mainly correlated to the developer concentration, possibly also to the polymer resin molecular weight and the polymer / PAC ratio etc. We added our study of its photochemistry property (here specifically the UV-vis absorbance or optical density), provided its spectroscopic response figures with respect to the sequentially increased exposure of the resist on quartz (250 - 550 nm and 300 - 450 nm). The relationship of the photographic contrast and its photochemistry property of the resist was briefed.

Select this Article		Theoretical study of a quantum dot microcavity laser Guangcun Shan and Shuying Bao Proc. SPIE 6279, 627925 (2007); http://dx.doi.org/10.1117/12.725218 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Here we theoretically investigate a new laser device structure model based on a single semiconductor quantum dot (QD) gain emitter, where the lasing occurs through discrete conduction states. A single QD is selectively placed in a high quality microcavity, called a microdisk, which is resonant with an intersublevel QD transition. The quantitative results of fully quantum-mechanical treatment here show that, when adjusting the QD-cavity coupling parameters to be appropriate values, the microcavity coupling mode would lead to a very high photon intensity of the single QD microcavity laser. The QD-cavity coupling interaction is modeled in the strong-coupling regime, and we conclude that the present QD microcavity system itself can serve as a new novel terahertz laser with low threshold.

Select this Article		Spectral analysis of pulse-width jitter of optical pulse trains Yun-cai Wang and Jun-hua Tang Proc. SPIE 6279, 627926 (2007); http://dx.doi.org/10.1117/12.725220 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We propose a technique for measuring the pulse width jitter of high repetition rate optical pulse trains. The technique is based on spectral measurement of three different harmonics of the detected pulse train. The simulation results show that the pulse width jitter would contribute a great amount of noise power to the total noise power when the product of pulse width and angular frequency is larger than 1. We apply the proposed technique to characterize noise of a Fabry-Perot Laser Diode. The pulse width jitter is estimated to be 2.3ps. Compared with the calculated 1.8% amplitude noise and 5.1ps timing jitter, the pulse width jitter is found not to be negligible.

Select this Article		New background estimation and suppression algorithm via Zernike-facet model Mou-fa Hu and Zeng-ping Chen Proc. SPIE 6279, 627927 (2007); http://dx.doi.org/10.1117/12.725223 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new background estimation and suppression algorithm was presented. In the algorithm, targets and observing noises were considered as mixed interferences of the image background. With this situation, image background was estimated adaptively and then background suppression was done in order to improve the signal-to-noise ratio (SNR) of targets. In this algorithm, firstly, a Zernike-facet model of image background was built up. Secondly, the total least squares (TLS) method was used to solve parameters of the model. Finally, background estimation and suppression were done using the model and its parameters. Simulations and several experiments demonstrating the effectiveness of this proposed algorithm were reported. And results show that this algorithm can be effective to estimate background in mixed noise environment and can preserve detail information of targets and improve SNR of targets. As a result, detecting probability and false probability will be improved in next process for automatic target detection and tracking.

back to top

Detonics, Ballistics, and Dynamic Materials Response

Select this Article		Recording of essential ballistic data with a new generation of digital ballistic range camera Graham P. Haddleton and Jo Honour Proc. SPIE 6279, 627928 (2007); http://dx.doi.org/10.1117/12.725225 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Scientists and Engineers still require to record essential parameters during the design and testing of new (or refined) munitions. This essential data, such as velocities, spin, pitch and yaw angles, sabot discards, impact angles, target penetrations, behind target effects and post impact delays, need to be recorded during dynamic, high velocity, and dangerous firings. Traditionally these parameters have been recorded on high-speed film cameras. With the demise of film as a recording media a new generation of electronic digital recording cameras has come to be accepted method of allowing these parameters to be recorded and analysed. Their obvious advantage over film is their instant access to records and their ability for almost instant analysis of records. This paper will detail results obtained using a new specially designed Ballistic Range Camera manufactured by Specialised Imaging Ltd.

Select this Article		Supersonic projectiles in the vicinity of solid obstacles Jamie P. Purdon, Neil R. Mudford, and Harald Kleine Proc. SPIE 6279, 627929 (2007); http://dx.doi.org/10.1117/12.725226 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Solid obstacles close to (but not in) the flight path of supersonic projectiles influence the flow field and thus possibly the projectile trajectory, even if no contact between projectile and obstacle occurs. In order to qualitatively clarify the basic characteristics of such projectile/obstacle interactions, an initial investigation comprised of two different sets of experiments has been conducted: live rounds were fired from a rifle so that they passed over a flat plate at distances between 0.8 and 2.5 projectile diameters in the first set of tests, followed by a second set where a stationary projectile model was placed in a supersonic wind tunnel to replicate the flow fields of the live range experiments. Time-resolved monochrome schlieren visualization was used as the primary diagnostic tool in the first set of experiments, while singleshot color schlieren images were obtained in the wind tunnel tests.

Select this Article		Analysis of base fuze functioning of HESH ammunitions through high-speed photographic technique T. K. Biswal Proc. SPIE 6279, 62792A (2007); http://dx.doi.org/10.1117/12.725229 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High-speed photography plays a major role in a Test Range where the direct access is possible through imaging in order to understand a dynamic process thoroughly and both qualitative and quantitative data are obtained thereafter through image processing and analysis. In one of the trials it was difficult to understand the performance of HESH ammunitions on rolled homogeneous armour. There was no consistency in scab formation even though all other parameters like propellant charge mass, charge temperature, impact velocity etc are maintained constant. To understand the event thoroughly high-speed photography was deployed to have a frontal view of the total process. Clear information of shell impact, embedding of HE propellant on armour and base fuze initiation are obtained. In case of scab forming rounds these three processes are clearly observed in sequence. However in non-scab ones base fuze is initiated before the completion of the embedding process resulting non-availability of threshold thrust on to the armour to cause scab. This has been revealed in two rounds where there was a failure of scab formation. As a quantitative measure, fuze delay was calculated for each round and there after premature functioning of base fuze was ascertained in case of non-scab rounds. Such potency of high-speed photography has been depicted in details in this paper.

back to top

Opto-Mechanical High-Speed Cameras

Select this Article		Developments and achievements of optomechanical high-speed photography in China Jingzhen Li Proc. SPIE 6279, 62792B (2007); http://dx.doi.org/10.1117/12.725232 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The theories and technologies of the optomechanical high speed photography, which has basically met the requirements in investigations of high speed, ultrahigh speed and other top scientific phenomena, have been developed and improved these years in China. Compared with the high speed photography with converter tube, the optomechanical high speed photography has a higher spacial resolution, larger image, and more frames since it only need one transfer from optical image to chemical image or charge image. Optomechanical high speed photographic techniques include high speed optics and mechanics, high speed optoelectronics, high speed electrooptical shutter, and high speed opto-optical technique. In this paper, we will introduce the technologies of high speed transporting film photography, ultrahigh speed rotating mirror photography, multiframe high speed photography with solid imaging unit, microscopy high speed photography, raster principle and Cranz-Schardin principle in high speed photography, and extreme high speed photography based on optical principles.

Select this Article		Detecting system based on framing camera for suspension array Yan Shi, Xuxiang Ni, and Zukang Lu Proc. SPIE 6279, 62792C (2007); http://dx.doi.org/10.1117/12.725233 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High speed imaging technology has been applied on biomedical research for a long history. Suspension array technology is a new generation of biochip, which was widely used in fields of life science and analytical chemistry, and was developed quickly. This study present a detecting system based on framing camera for suspension array. In suspension array microspheres were used as the carrier of bio-probes and microchannels were used as analyzing platform. By pre-dyeing of fluorophores in microbeads, the addressing of microbeads was implemented by optical coden. Bio-probes attached to microbeads were distinguished by intensity of fluorescence. Suspension array was usually detected with flow cytometry serially, which was slow relatively. Then a 2D parallel measurement system based on framing camera for suspension array was established in order to increase the measurement speed. Liquid sample containing microsphere was injected into microchannel by a 100ul syringe connected by a capillary. Microspheres flowing in the microchannel form a 2D layer, which was illuminated freezingly by a pulsed Xenon lamp and imaged by a microscopy objective in parallel. The microfluidic channel was designed and fabricated, which was a rectangle microchannel of 1mm×50um in cross-section. The image was captured by CCD and transmitted into computer by frame grabber. Image was processed to distinguish microspheres extract information from the background. Thus area measurement of suspension array in microchannel was realized. Compared with flow cytometry, this technology increased analyzing rate greatly, which could be thousands of microspheres per second.

back to top

Poster Session: Image Converter Streak and Framing Cameras

Select this Article		Test of Russian K004M image converter camera when recording natural lightning in Florida V. B. Lebedev, G. G. Feldman, B. N. Gorin, V. A. Rakov, M. A. Yuman, and R. K. Olsen Proc. SPIE 6279, 62792D (2007); http://dx.doi.org/10.1117/12.725235 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The results of K004M camera tests when recording a trigger lightning are presented in paper [1] at this Congress. This report is a continuation of paper [1] and gives the results of demonstration of the camera functioning when recording a short spark in laboratory of the University of Florida (Gainesville, USA) and then a natural lightning in the University and at the International Center for Lightning Research & Testing (ICLRT) in Camp Blanding that belongs to this University. In so doing it has been shown that, except for luck, important conditions of successful record of a natural lightning are exact synchronization of the moment of camera start with a required discharge stage as well as automatic measurement of a distance to lightning and determination of its polarity.

Select this Article		Observation of vacuum arc cathode spot with high-speed framing camera Maxim B. Bochkarev, Vitaly B. Lebedev, and Gregory G. Feldman Proc. SPIE 6279, 62792E (2007); http://dx.doi.org/10.1117/12.725236 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A copper vacuum arc cathode spot at current 10-100 A was imaged by three-frame camera K 0011 (BIFO Company, Russia) with frame exposures 30 ns and 6 ns and spatial resolution up to 7 m. It was found that spot splitting into separate fragments occurs at currents higher than 50 A. The average fragment size was found to be 20 m at current about 10 A (cathode spot consists of a single fragment). With the rise of the arc current the average fragment size rises too and reaches 50 μm at current 100 A (cathode spot consists of two or three fragments). The overall dimension of region occupied by cathode spot fragments rises from 20 m at current 12 A to 120 m at current 100 A. Observations with high temporal resolution (exposure time 6 ns) reveal the significant changes of cathode spot brightness occurring within about 10 ns time interval.

Select this Article		Model for the brightness uniformity of fluorescence screen of image intensifier YaFeng Qiu, BenKang Chang, YunSheng Qian, RongGuo Fu, Youtang Gao, and Tian Si Proc. SPIE 6279, 62792F (2007); http://dx.doi.org/10.1117/12.725237 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The three elements of photoelectrical cathode, microchannel plate and fluorescence screen are important parts to imaging quality of low light and ultraviolet Image intensifier. To do research and analysis work on the Fluorescence screen parameter testing have practical significance to the understanding of the performance of fluorescence screen and then can help to know where improvement should be made and then achieve a best performance entire tube, This article mainly introduce the testing theory of the brightness uniformity of fluorescence screen of Image Intensifier and how to build a mathematic model.

Select this Article		The streak camera system in HLS J. G. Wang, B. G. Sun, Y. Cao, and B. Y. Wang Proc. SPIE 6279, 62792G (2007); http://dx.doi.org/10.1117/12.725241 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract HLS (Hefei Light Source) is an 800MeV electron storage ring in National Synchrotron Radiation Laboratory. To measure electron bunch for Synchrotron Radiation and to understand the machine behavior during the operation, the streak camera system has been built in HLS storage ring on April 2006. The streak camera system mainly consists of the synchrotron light extracting optics setup and OPTOSCOPE the streak camera. The light extracting optics setup consists of the light extracting path and the optics imaging system. The OPTOSCOPE the streak camera consists of a camera main unit with input optics, a remote control unit, a CCD camera readout unit, a power supply unit, a Personal Computer with a frame grabber interface card and ARP-Optoscope software package. The streak camera system operates with synchroscan sweep mode or dual time base sweep mode. Controlling the streak camera and image acquisition is made by the ARP-Optoscope software. At present, the system is used to measure the bunch length and the bunch interval in HLS storage ring. Some typical results of the measurement are given.

Select this Article		Framing camera applied in the diagnostics of the pumping source performance Li Yu, Jing-ru Liu, Ai-ping Yi, Lian-ying Ma, Chao Huang, and Xiao-xia An Proc. SPIE 6279, 62792H (2007); http://dx.doi.org/10.1117/12.725252 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Taking advantage of the framing camera, the performances of the laser pumping source were studied. The framing photographs of XeF₂ photodissociation wave (PDW) under different experimental conditions had been taken, which showed the forming process of the PDW. The variations of the radius, thickness and developing velocity of the PDW with time had been obtained under different XeF₂ initial concentrations. The temporal and spatial characteristics of the PDW had been analyzed. The irradiative intensity of pumping source could be diagnosed by calculating the time evolution of XeF₂ photodissociation wave which was photographed by framing camera. The framing photographs of the discharge plasma channel under different conditions had been obtained. The effect of the discharge plasma extension on the efficiency resistance of the discharge circuit had been analyzed.

Select this Article		Theoretical analysis of a time focus and time amplifier cavity in streak tube J. Liu, L. Niu, J. Li, J. Shi, H. Liao, W. Peng, Q. Yang, and H. Niu Proc. SPIE 6279, 62792I (2007); http://dx.doi.org/10.1117/12.725255 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract During the last few years, The time resolution of X-ray streak cameras have been improved to near 300-fs. Due to the relative slower sweeping speed and initial energy distribution of electrons, It is hard to breakthrough the 100 fs time resolution barrier. In this letter, time focus and time amplifier system is proposed. The time focus system is used to compensate the time dispersion between photocathode and anode. The using of a time amplifier improves the technical time resolution. The time focus and time amplifier system is designed to a compact fast electrons cavity structure.

Select this Article		Octagonal pyramid optical splitting system in nanosecond framing camera Baozhong Shan, Baoping Guo, Shuyan Wang, and Hanben Niu Proc. SPIE 6279, 62792J (2007); http://dx.doi.org/10.1117/12.725256 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The high-speed photography is essential diagnostic tool in research on the ultra fast process. Usually, such process has the duration of hundreds nanoseconds to dozens microseconds. The image diagnostic instrumentation is required to obtain high speed framing images, which should be in fixed time in the duration with short exposure time and suitable gap. A kind of nanosecond framing camera has been developed, which uses octagonal pyramid mirror to split one image to eight. One image is split to eight in the space and each split image has equal optical energy. A nearly-pasted image intensifier with gate selection is also developed to enhance the weak optical image. Each channel uses independent image intensifier with gate and CCD camera. This system can capture eight images one time in the minimum interval time of 10ns while the exposure time is 3ns The framing speed achieves 100 million/second. The dynamic spatial resolution achieves 15 lp/mm. Many experiments, such as beam diagnose of electron pulse, plasma luminescence process have adopted this camera and many useful results have been obtained.

Select this Article		A 3D framing camera with pulse laser and modulated receiver Xiuda Zhang, Huiming Yan, Yanbing Jiang, and Shenbao Yin Proc. SPIE 6279, 62792K (2007); http://dx.doi.org/10.1117/12.725257 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It is convenient to apply three-dimensional (3D) detecting instruments to automatic drive, virtual reality modeling, terrain reconnaissance, etc. It is presented that a new high-speed camera which achieves one three-dimensions image by only one light pulse in this paper. It has a measurement range of one kilometer and a distance resolution of five meters. This camera is composed with a pulse laser and three receivers which are made up with a Micro Channel Plate (MCP) and a Charge Coupled Device (CCD) each. These parts are mature commercial productions that provide low cost and high reliable to the 3D camera. As soon as the pulse laser emits a light pulse, the three receivers are modulated with synchronistical control circuits. A 3D picture can be calculated by three different density images which are obtained by that. The one-light-pulse-one-picture mode gives a flexible way to work with a gate signal. A 3D camera working with high-speed gate signal can achieve high-speed photography easily. A mathematic model is established to describe measurement range, distance detection precision and space resolving of the camera. The best modulation functions of the receivers are given with consideration of white noise by Euler-Lagrange equation. Due to the best modulation function we give a scheme is follows: The first receiver is modulated by a const gain, the second one is modulated by a linearly increasing gain and the last one is modulated by a linear decreasing gain. This combination achieve both low noise and simple structure. Because of the simple structure, several fibers which we named amending fibers can be used to amend error of receiver modulation and synchronistical error. Analysis of the detection precisions of the camera and continuous wave detection systems are carried out both in time domain and frequency domain. The results indicate pulse laser can increase the detection range by suppressing background light greatly and decreasing imaging time. But it achieves lower precision if the background light is faintness. Simulation experiment results are presented in this paper. A 1.4 kilometers fiber was used in this experiment to simulate a 700 meters distant, a Laser Diode (LD) is employed to simulate the pulse laser. A high voltage modulation circuit was designed to modulate the gain of MCP to implement the modulation function. The experiment results with and without amending fibers indicated that the primary noises come from CCD and the high voltage modulation circuit. The amending fibers can weaken the circuit errors in some degree. Future improvement is described in the end of the paper also.

back to top

Poster Session: Image Processing and Data Analysis

Select this Article		Rapid regularization of LIDAR point cloud based on fractal interpolation with enhancement of edge features Shengwang Zhang and Youchuan Wan Proc. SPIE 6279, 62792L (2007); http://dx.doi.org/10.1117/12.725260 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The basic fractal theory and the fractal interpolation are studied, and the fractal property of remote sensing images is refered in this paper. As to LIDAR points data, due to its difficulty of being handled by the traditional arithmetics, a arithmetic of rapid regularization of LIDAR point cloud based on fractal interpolation with enhancement of edge features is proposed on the analysis of the organizing forms of the point cloud. The arithmetic regularizes the points cloud into a "rough image" by direct resample, and the edge pixels are differentiated from it, which are given new value by fractal interpolation. And the non-edge ones retain their original value. The experiment proves that it can reduce the computation, and enhance the main features effectively.

Select this Article		Edge detection and contour tracing of medical cell images Luping Xu, Jingrong Sun, and Lexuan Xi Proc. SPIE 6279, 62792M (2007); http://dx.doi.org/10.1117/12.725262 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It is important for medicine cell image to detect edge and trace contour In the process of recognition. The method of equilibrium is used to improve the contrast between the target and the background for giving prominence to the target at the beginning in this paper. Then edges in the image are detected with Canny operator, followed by edge figures processing that utilizes fundamental transform processing in mathematical morphology. Finally, it makes use of eightdirection chain code searching algorithm to trace contour, and carry on vectorization to the traced contour by using improved variable-step-length algorithm in order to keep and recognize cells further. Better experimental results are obtained by utilizing this method on edge detection and contour tracing of cell images.

Select this Article		Research on multi-pixels edge detecting and matching Yu Liu, Yan-jun Li, Ke Zhang, and You-yi Jiang Proc. SPIE 6279, 62792N (2007); http://dx.doi.org/10.1117/12.725345 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Aiming at the influence of geometrical deformation on image matching, the method based on gray-level difference between the nearby pixels detecting multi-pixels edge of image is put forward. To a 256 by 256 image, it needs only 0.14 second to detect edge which is 40% and 35% faster respectively than that of the Prewitt and Robert arithmetic. Applying the method based on multi-pixels edge character to image matching, the influences of edge excursion can be improved obviously: when excursion exists in single pixel point, the relative probability of image matching is improved to 67%; when it exits in edge, it is improved to 50%. Research shows that this method is of simple model, high real-time quality and anti-geometrical-deformation. Most importantly, it is simply conducted.

Select this Article		Effects of exposure time on the image in atmospheric turbulence Chong Gao, Jing Ma, and Li-Ying Tan Proc. SPIE 6279, 62792O (2007); http://dx.doi.org/10.1117/12.725350 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image distortions during the propagation of optical beam in the turbulent atmosphere are provoked. Exposure time has effect on the space distribution characteristics of light image in the focal-plane CCD or CMOS sensor. The effect of exposure time on the spot size and shape is analyzed both theoretically and experimentally. The expression of spot size variable with exposure time has been developed from the angle-of-arrival fluctuation by the longitudinal and transverse components. In an optical free-space laser transmission experiment over a three-month period, measurements of spot size at variable exposure times are shown. Theoretical and experimental results illuminate the important point that the effect of exposure time must be considered for the optical design. The results show that the spot size decreases with exposure time increasing. A rapid decrease is showed in the spot size for short exposure times up to about 20msec.

Select this Article		3D motion estimation for multi-object relative motion parameter and the centre of rotation using stereo sequence images Wanpeng Cao, Rensheng Che, Dong Ye, and Hua Chen Proc. SPIE 6279, 62792P (2007); http://dx.doi.org/10.1117/12.725354 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper proposes a general rigid motion model for estimating the multi-object 3D relative motion parameters and the centers of rotation based on stereo sequences images. It is assumed that the correct establishing correspondence between the matching points has been accomplished. For arbitrary two objects of these motion objects, firstly we set up three space reference frames respectively on the two objects and the left camera, and their space relation is described according to the coordinates of the correspondence points that lie on the two objects. Then, we design the two objects' 3D motion model through analyzing the rigid motion objects' character under the three reference frames. Thirdly, using these points' 3D space coordinates acquired by high speed stereo photography, we can linearly figure out the instantaneous relative 3D motion parameter and center of rotation through long sequence images after eliminating the motion affection of the other motion object. For heightening the motion estimation method's robust, RANSAC algorithm is applied to delete the outliers. Finally, simulation experiments are conducted using synthesized stereo sequence images corrupted by noise and the experiment results prove the model's correction and the algorithm's validity.

Select this Article		Real-time 3D shape acquisition using a novel rotatable interlaced coded structured light Li Xu, Zhijiang Zhang, He Ma, and Zhihua Dong Proc. SPIE 6279, 62792Q (2007); http://dx.doi.org/10.1117/12.725398 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract According to Sampling Theorem and image processing, structured light system has some limits, such as the measurement resolution is restricted, some little gaps can not be measured and there are some errors or lost data on the border of surface. A novel rotatable interlaced coding in real-time system of 3D information acquisition using structuredlight imaging is proposed. It is consisting of two free directions of three-frame space-time light pattern, which can acquire the denser 3D data from a single viewpoint. It can decrease the error from range image registration and advance the system accuracy. The paper builds a real-time system of 3D profile measurement using structured-light. It allows a hand-held object to rotate freely in the space-time coded light field, which is projected by the projector.

Select this Article		A noise removal algorithm for LIDAR intensity image based on orientation gradient and weighted threshold Shengwang Zhang and Youchan Wan Proc. SPIE 6279, 62792R (2007); http://dx.doi.org/10.1117/12.725449 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, an algorithm of LIDAR intensity image noise removal based on orientation gradient and weighted threshold is proposed on the analysis of LIDAR imaging mechanism. It detects and removes the noise in LIDAR intensity image based on the orientation gradient of the ground got from LIDAR distance information, during which weighted threshold is adopted to calculate the threshold automatically. Experiments prove that this filter can detect and remove the noise effectively and preserve the edge information of Intensity Image better.

Select this Article		The edge detection of hyperspectral image based on its proportion image Yanjun Gong and Dongmei Bi Proc. SPIE 6279, 62792S (2007); http://dx.doi.org/10.1117/12.725450 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Intensity-based edge detectors cannot distinguish whether an edge is caused by material changes. Therefore, our aim is to classify the physical cause of an edge using hyperspectral obtained by a spectrograph. A method is presented to detect edges in hyperspectral images. Analyzing proportion images of a hyperspectral image, we implement edge detection of the hyperspectral image by using its proportion images. In edge part of hyperspectral image, the endmembers proportion of mixed pixels is very small value. Edge detection can be implemented through these the distinctness of endmember proportion in edge part. The method of edge detection is called edge detection based proportion image about hyperspectral images.

Select this Article		A new image-reconstruction approach to optical computed tomography based on BP neural network Qiong Wu and Zhiyu Qian Proc. SPIE 6279, 62792T (2007); http://dx.doi.org/10.1117/12.725453 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new image reconstruction approach to optical computed tomography is proposed in which a BP neural network is used to express the nonlinear relation between the change of optical properties inside the biology tissue and photons distributing change around the surface. A modeling and simulation tool named Femlab and finite element method has been tested wherein the forward model on a basis of the diffusion equation. Based on the forward problem, a BP neural network was established to solve the inverse problem. Thus, the position and its corresponding optical properties of tissue change could be recognized by the network. New approach was suitable for clinical application for its fast reconstruct characteristic.

Select this Article		Averaging algorithm of reticle images in low-level-light weapon sight based on impact condition Youtang Gao, Benkang Chang, Si Tian, Yafeng Qiu, Jianliang Qiao, and Rongguo Fu Proc. SPIE 6279, 62792U (2007); http://dx.doi.org/10.1117/12.725455 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The novel approach to the image noise problem of reticle images based on impact condition in low-level-light weapon sight is proposed in this paper. The condition and process of the low-level-light weapon sight impact experiment were analyzed, and then averaging algorithm of reticle images consists of two parts has been applied on the experiment. First averaging and smoothing using a rotating mask methods were operated on Gaussian noise, to obtain a matching precision with in 0.05 mil. Second the well known efficient median filtering smoothing method is performed to obtain the higher matching precision. The potential of this averaging method is shown in the experimental results of reticle images in low-level-light weapon sight based on impact condition.

Select this Article		Real-time phase correction of optical images using adaptive optics system based on MEMS technology Jie Li, Haiqing Chen, Peng Wu, and Huihui Li Proc. SPIE 6279, 62792V (2007); http://dx.doi.org/10.1117/12.725459 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The possibility of compensating the wave-front distortion of an optical imaging system in real time has been a subject of considerable interest. To compensate the wave-front aberration resulted by atmospheric turbulence, random gravity, heat and component surface error during manufacturing, adaptive optics is an effective way. But conventional adaptive optics has not found widespread acceptance outside the high-end astronomy community due to the cost and complexity. With the development of micro-electro-mechanical systems (MEMS) based on silicon micromaching technology, it is possible to develop a low-cost adaptive optics system. In this paper we will describe a micro-adaptive imaging system that has proved the practical feasibility of real time optical phase correction. As a key component in our adaptive optics system, a novel silicon bulk micromaching deformable mirror was used to compensate the wave-front aberration of optical image . The laboratory experiments are also presented to reveal the benefit that such system can provide. Future possible improvements are addressed as well.

Select this Article		A temporal algorithm for IR small targets detection Hongshan Nie, Xi Tian, and Zhenkang Shen Proc. SPIE 6279, 62792W (2007); http://dx.doi.org/10.1117/12.725461 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In order to detect small dim targets in IR image sequences, a temporal processing technique is investigated. Based on the temporal difference models for background noise pixel, target pixel and clutter pixel, we formulate the detection problem in 2 steps, Cross Correlation Target Detection method (CCTD) and Generalized Likelihood Ratio Test (GLRT). After CCTD step, noise pixels in the image sequences are almost suppressed and only target pixels and a few clutter pixels can pass the detection threshold. In order to further the targets detection in these pixels, an improved GLRT method is developed. This improved GLRT method can suppress the clutter pixels sequentially and enhance the performance of the temporal detection method. Theoretical analyses show that this algorithm can detect targets on very high detection probability and very low false alarm probability. The effectiveness of the technique is demonstrated by applying it to real world infrared image sequences containing cloud clutter and airplanes flying at long range.

Select this Article		Quantitative evaluation of laser jamming effect on imaging systems Wei Gao Proc. SPIE 6279, 62792X (2007); http://dx.doi.org/10.1117/12.725465 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper is devoted to a study of methods for quantitatively evaluating the jamming effect of a laser jamming device on electro-optical imaging systems. Based on the theory of digital image processing and the Johnson criterion for target detection and discrimination, four evaluation rules for laser jamming effect on electro-optical observation and aiming devices are proposed. For the target-discrimination-grade, target-discrimination-probability, or target-discriminationrange rule, the laser jamming effect is evaluated respectively according to the change of the target discrimination grade, probability, or range of the imaging system after being jammed. For the correlativity rule, the jamming effect is determined according to the correlativity between the two images of the imaging system before and after being jammed. In order to evaluate laser jamming effect on electro-optical search and track systems, three evaluation rules are proposed for the three working stages of the imaging system. At the searching or capturing stage, the jamming effect could be evaluated respectively according to the change of the target detection or capture probability of the imaging system after being jammed. At the tracking stage, whether the imaging system under jamming could produce effective tracking errors, or whether the tracking errors exceed three times its normal tracking accuracy is proposed as the criterion for determining whether the jamming is effective or not, and the jamming effect could be graded according to the jamming success rate for numbers of tests. Finally, the test methods for laser jamming effect on electro-optical imaging systems are discussed.

Select this Article		Small target fusion detection algorithm via image neighborhood entropy and univalue segment assimilating nucleus principle Mou-fa Hu and Zeng-ping Chen Proc. SPIE 6279, 62792Y (2007); http://dx.doi.org/10.1117/12.725268 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Small and dim targets detection in the presence of strong background clutter is a challenging problem faced in many applications including space surveillance and missile tracking. To solve this problem, a new fusion detection algorithm applied image neighborhood entropy and univalue segment assimilating nucleus (USAN) principle is presented. In this method the neighborhood entropy is used to locate small and dim targets. And the USAN principle is used to extract some geometry features of targets including edges and inflexions. Based on these results, image fusion method is used to detect real targets from noise and false targets. Finally, an iterative image threshold technique is proposed to label and locate targets more precisely. Simulations and experiments show that the new fusion detection algorithm takes advantage of the USAN principle and the neighborhood entropy method and it can detect small dim targets robustly, fast and efficiently.

Select this Article		Correlation detection filter for imaging laser radar Jianfeng Sun, Qi Li, Wei Lu, and Qi Wang Proc. SPIE 6279, 62792Z (2007); http://dx.doi.org/10.1117/12.725269 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Laser radar can simultaneously produce the intensity and range images, and the space resolution is high, so the recognition performance is well, and it can choose the aim point of target. Laser radar is applied to many fields, such as guidance, navigation, and becomes the research hot point in recent years. In the vertical detection of laser radar, the algorithm is required not only solving in-plane rotation-invariant problem, also the distortion-invariant problem, and it must satisfied the real-time. Correlation algorithm is a parallel processing procedure, detecting many targets at one time, and its design can be implemented on the high speed digital signal processor. In the paper, a new filter named CHF-MACH filter is presented, which combine multiple circular harmonic expansions into one filter through MACH criteria. Because of the filter having the characters of the two filters, it can solve the problems of in-plane rotation-invariance and distortion-invariance simultaneously, and meet the real-time requirement. The simulated range image of laser radar is regarded as research target, and computing the PSR (peak to sidelobe ratio) values of correlation output of the different objects, and plotting the PSR curves of the different angles. Simulating the scene of laser radar which includes multiple objects, CHF-MACH filter performance is validated through testing with the different angles for the objects, and the non-training images can obtain the well correlation output.

Select this Article		Optimizing image normalization algorithm for shape distortions Junjie Liang and Yucai Feng Proc. SPIE 6279, 627930 (2007); http://dx.doi.org/10.1117/12.725322 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In general, there are four basic forms of planar shape distortion caused by changes in viewer's location: rotation, scaling, translation and skewing. For a good shape descriptor should be invariant to these distortions, a shape can be normalized before feature extraction. Due to the drawbacks of the normalization algorithm, shape compacting proposed by J. G. Leu, which normalizes rotation and skewing distortions incompletely, an optimized shape normalization algorithm is proposed in this paper. The basic idea is first to get the compact shape which is invariant to translation and scaling distortions by the shape compacting. Then, on determining the principal axis of the object shape, we get the angle included between the x-axis and the principal axis, according to which the shape is rotated. Finally, the reversed object shape can be normalized by the signs of the original image's central moments. Therefore, we can normalize a shape and its distorted versions into a single one, with the following feature descriptor invariant to the above four distortions. The results of our experiments demonstrate that the optimal shape normalization algorithm outperforms the existing shape compacting.

Select this Article		An automatic target recognition algorithm based on image matching with multiple sub templates Li Zhi Qian, Da Zheng Zhao, Shen Xiang Tao, and Gang Li Proc. SPIE 6279, 627931 (2007); http://dx.doi.org/10.1117/12.725323 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper presents an upgrade target recognition algorithm based on the analysis of normal template matching algorithm. The new algorithm firstly uses given template to generate sub templates at random or with certain principle, and then matches each sub templates in search image to get possible areas of target, lastly finds the target from comparison among the matching results. The paper at last gives the test results of the mentioned Algorithm. The results show: the new algorithm greatly improves the efficiency, real-time ability, precision of the normal algorithm, and also it has an advantage of easy realization, thus it is a good reference for solving the same problems.

Select this Article		Modified simultaneous algebraic reconstruction technique and its application to image reconstruction Chunfang Li Proc. SPIE 6279, 627932 (2007); http://dx.doi.org/10.1117/12.725324 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image reconstruction from projection is usually encountered in computerized tomography (CT) diagnosis. Based on the factors of economy and practicality, optical CT is now developing in the direction of reconstruction from fewer views or limited view range. However, in this condition, conventional simultaneous algebraic reconstruction technique (SART) has shown some shortcomings. A modified simultaneous algebraic reconstruction technique (MSART) is presented here, which takes into account not only the pixel value but also the segment length of the intersecting ray in error-correction procedure. The computer simulation makes comparing studies of SART and MSART. The results show that MSART solves the edge distortion effectively and makes encouraging improvement in reconstruction quality with sparse data. Even applied to image reconstruction from projection with noise, MSART works well.

Select this Article		Spatial fusion algorithm of multispectral and high-resolution panchromatic images Luping Xu and Jing Yao Proc. SPIE 6279, 627933 (2007); http://dx.doi.org/10.1117/12.725326 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image merging based on wavelet transformation requires a large computation complexity and may cause a severe lost of the spectral information of the multispectral image. A new spatial image fusion algorithm based on fuzzy theory is proposed in this paper. Through calculating the neighborhood homogeneous measurement (NHM) with the fuzzy entropy, the structure information of the high-resolution panchromatic image was obtained. Two thresholds were defined for different rules of fusion. Therefore, different fusion operations were taken accordingly. Experimental results demonstrate that the proposed algorithm enhances spatial detail information of the merged image greatly and has a better ability to preserve spectral information of the original multispectral image, compared with a wavelet image merging algorithm.

Select this Article		Analysis on the cophasing errors of optical sparse-aperture imaging system Dayong Wang, Hancheng Liu, Ji Han, Hongfeng Guo, Xiyang Fu, and Shiquan Tao Proc. SPIE 6279, 627934 (2007); http://dx.doi.org/10.1117/12.725327 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Optical sparse-aperture imaging system is one of the most potential techniques which can break through the physical limits to the diameter of conventional filled aperture telescope. The image from individual telescope not only should be overlapped, but also have the same phase at image plane. The purpose of this paper is to study the cophasing errors which would degrade the performance of sparse-aperture imaging system. The analysis and discussion on system errors which would lead to the cophasing error is presented, including piston error, tip/tilt error and pupil mapping error. The results of the numerical simulation are presented on the system which has two sub-systems and certain parameters. The effects of the piston error and tip/tilt error on the point spread function (PSF) of the system are discussed. The image degradation due to the piston and tip/tilt errors are shown based on the imaging system which has three subsystems.

Select this Article		Study on real-time images compounded using spatial light modulator Jin Xu, Zhebo Chen, Xuxiang Ni, and Zukang Lu Proc. SPIE 6279, 627935 (2007); http://dx.doi.org/10.1117/12.725328 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image compounded technology is often used on film and its facture. In common, image compounded use image processing arithmetic, get useful object, details, background or some other things from the images firstly, then compounding all these information into one image. When using this method, the film system needs a powerful processor, for the process function is very complex, we get the compounded image for a few time delay. In this paper, we introduce a new method of image real-time compounded, use this method, we can do image composite at the same time with movie shot. The whole system is made up of two camera-lens, spatial light modulator array and image sensor. In system, the spatial light modulator could be liquid crystal display (LCD), liquid crystal on silicon (LCoS), thin film transistor liquid crystal display (TFTLCD), Deformable Micro-mirror Device (DMD), and so on. Firstly, one camera-lens images the object on the spatial light modulator's panel, we call this camera-lens as first image lens. Secondly, we output an image to the panel of spatial light modulator. Then, the image of the object and image that output by spatial light modulator will be spatial compounded on the panel of spatial light modulator. Thirdly, the other camera-lens images the compounded image to the image sensor, and we call this camera-lens as second image lens. After these three steps, we will gain the compound images by image sensor. For the spatial light modulator could output the image continuously, then the image will be compounding continuously too, and the compounding procedure is completed in real-time. When using this method to compounding image, if we will put real object into invented background, we can output the invented background scene on the spatial light modulator, and the real object will be imaged by first image lens. Then, we get the compounded images by image sensor in real time. The same way, if we will put real background to an invented object, we can output the invented object on the spatial light modulator and the real background will be imaged by first image lens. Then, we can also get the compounded images by image sensor real time. Commonly, most spatial light modulator only can do modulate light intensity, so we can only do compounding BW images if use only one panel which without color filter. If we will get colorful compounded image, we need use the system like three spatial light modulator panel projection. In the paper, the system's optical system framework we will give out. In all experiment, the spatial light modulator used liquid crystal on silicon (LCoS). At the end of the paper, some original pictures and compounded pictures will be given on it. Although the system has a few shortcomings, we can conclude that, using this system to compounding images has no delay to do mathematic compounding process, it is a really real time images compounding system.

Select this Article		An adaptive lifted pyramid for image compression Jingbo Xiang, Hongwu Su, and Xiuqin Su Proc. SPIE 6279, 627936 (2007); http://dx.doi.org/10.1117/12.725332 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, an improved Laplacian pyramid is proposed. We introduced additional adaptive lifted steps in the Laplacian pyramid. Our pyramid is able to control efficiently the entropy of detail image. Hence, it provides improved coding performance when compared to the standard Laplacian pyramid. Simulation results show that coding gains of up to 1 dB for images when compared to the standard Laplaican pyramid, and the adaptive lifted Laplacian pyramid have significantly lower entropy values.

Select this Article		Decorrelate hyperspectral images using spectral correlation Liang Chen, Daizhi Liu, and Shiqi Huang Proc. SPIE 6279, 627937 (2007); http://dx.doi.org/10.1117/12.725335 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper proposes a new algorithm for lossless compression of hyperspectral images. In our work we found hyperspectral data have unique characteristic based on spectral context and adjacent pixel spectral vectors (curves) highly correlate with each other. Pearson correlation coefficient is an effective measure of spectral similarity between spectral curves to detect horizontal and vertical spectral edge. Thus, spectral correlation is used to prediction in spectral direction for decorrelation of lossless compression of hyperspectral images. Experiments show the proposed algorithm is effective, and it's more important that it has much lower complexity than other algorithms.

Select this Article		A sub-pixel correlation tracking method for extended target based on hierarchy model Zhenming Peng, Anquan Guan, Shengjun Tian, and Xiaobing Fan Proc. SPIE 6279, 627938 (2007); http://dx.doi.org/10.1117/12.725340 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel algorithm for detecting and tracking extended target against cluttered background using the improved MPC distance and searching strategy with hierarchy model is presented in this paper. Comparing with the conventional methods, the proposed method modified the correlation distance for MPC criterion for classifying target and background as well, and designed an image shrinking methods controlled by the ratio of median filter and mean filter, which can improve the computation efficiency. Moreover, we interpolate the image within a small window to obtain high accuracy with the half pixels. Experimental results show, as compared to the conventional approaches, the proposed algorithm is more robust, higher precision and has simplified computational complexity for tracking extended target against cluttered background.

Select this Article		Study to real-time target recognizing system based on optical correlator Yong Zhang, Guangbin Feng, Rui Xue, and Pengcheng Yan Proc. SPIE 6279, 627939 (2007); http://dx.doi.org/10.1117/12.725342 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The recognition algorithm based on geometry texture character includes pattern matching, estimation function, and determination tree. The advantage of above algorithms is easy to be programmed and realized by computer. However, the recognizing operation consumes the mass of system source, which lead to the difficult to assure the good recognizing accuracy under the high recognizing speed. Optical correlation processing system transmits information by photons and operates by photo-electronic device, and realizes the target recognition by optical refraction, interference, and diffraction. Compared with traditional computer image processing techniques, optical correlation system offer primarily two types of benefits. On the one hand, optical correlation systems have an inherent capability for parallel processing, which can transmit rapidly mass information. On the other hand, it changes the complex images processing problem into spot recognizing in output plane. The correlation peak of high gray value appeared in the correlation plane can be used to the proof to tell target from many kinds noises. The analysis in paper to how to make the complex matching filter, how to determinate the truly correlation peak from others signal in correlation plane rely on neural nets technology could be helpful to the study of optical correlation system used to the field of image recognition.

Select this Article		A real time image sequence processing algorithm for target ranging Xiao-ning Fu, Shang-qian Liu, and En-ke Li Proc. SPIE 6279, 62793A (2007); http://dx.doi.org/10.1117/12.725346 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It investigated in an image sequence procession algorithm for finding the distance from a moving target in space to the mobile camera. Through 4-pairs points matching in adjacent image frame, the radial distance variation between adjacent sampling times was calculated, with the target's azimuth, pitching, characteristic linearity and the space coordinate of the camera jointed, a 4-order non-linearity equation was set up, distance from target to the camera at former time, i.e., the only meaningful solution to the equation was solved, then obtained the distance from target to the camera at this time. The ranging principle was explained, the ranging equation was deduced, the ranging error was analyzed, and the relative measurement data and experiment results were given. It was suggested by our research that this algorithm could estimate the distance from a moving target in space to the camera with only two image needed, an experiment was conducted to illustrate the effectiveness and the validity of the algorithm. This scheme is valid to any rigid target in three-dimension movement which could be superficially imaging and had a distance variation between adjacent sampling time meanwhile, the algorithm can be realized with DSP and VLSI chips at 25 frame per second.

Select this Article		Color image encryption based on fractional Fourier transforms and pixel scrambling technique Jianlin Zhao, Hongqiang Lu, and Qi Fan Proc. SPIE 6279, 62793B (2007); http://dx.doi.org/10.1117/12.725349 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Color image encryption based on fractional Fourier transform (FRT) and pixel scrambling technique is presented in this paper. In general, color (RGB) image cannot be directly encrypted using a traditional setup for optical information processing, because which is only adapted to process two-dimensional gray image. In the proposed method, a three-dimensional RGB image is decomposed to three two-dimensional gray images (R, G and B values of the color image), and the encryption operation will be done on each two-dimensional gray image, then the encoded color image is available by composing the three two-dimensional encrypted images. The decryption process is an inverse of the encryption. The optical encrypting systems based on the presented method is proposed and simulated. Some results of computer simulation are presented to verify the flexibility and the reliability of this method. The quality of decrypted images would be debased with the difference of the fractional order. The frustrated decryption of monochromic image will affect the color of decrypted image. At the end of this paper, an all-optical and photoelectric encryption/decryption systems solution are presented, and the principle of selecting optical devices are also given.

Select this Article		Morphology based adaptive preprocessing method of infrared image sequence Xiaochun Cai, Yihua Hu, Guilan Hu, Xiaohong Tao, and Wuhu Lei Proc. SPIE 6279, 62793C (2007); http://dx.doi.org/10.1117/12.725325 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper presents an adaptive preprocessing method for infrared image sequence. Firstly an adaptive structuring element (SE) construction algorithm is proposed. Secondly, based on morphological top-hat operation, the adaptive background suppression of image sequence is taken. Finally, the image sequence adaptive segmentation is achieved by using morphological opening operation. Some experimental results demonstrate that our proposed method is effective and adaptive for infrared image sequence preprocessing.

Select this Article		Non-uniform MR image reconstruction based on non-uniform FFT Xiao-yun Liang, Wei-ming Zeng, Zhi-hua Dong, Zhi-jiang Zhang, and Li-min Luo Proc. SPIE 6279, 62793D (2007); http://dx.doi.org/10.1117/12.725329 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A Non-Uniform Fast Fourier Transform (NUFFT) based method for non-Cartesian k-space data reconstruction is presented. For Cartesian K-space data, as we all know, image can be reconstructed using 2DFFT directly. But, as far as know, this method has not been universally accepted nowadays because of its inevitable disadvantages. On the contrary, non-Cartesian method is of the advantage over it, so we focused on the method usually. The most straightforward approach for the reconstruction of non-Cartesian data is directly via a Fourier summation. However, the computational complexity of the direct method is usually much greater than an approach that uses the efficient FFT. But the FFT requires that data be sampled on a uniform Cartesian grid in K-space, and a NUFFT based method is of much importance. Finally, experimental results which are compared with existing method are given.

Select this Article		An algorithm based on spatial filter for infrared small target detection and its application to an all directional IRST system Jun-hui Luo, Hong-bing Ji, and Jin Liu Proc. SPIE 6279, 62793E (2007); http://dx.doi.org/10.1117/12.725333 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For the small targets detection in single frame infrared image, a spatial filter algorithm based on an adaptive smooth filter and the Robinson Guard spatial filter is proposed in the paper. The algorithm can detect the small targets in the undulant background effectively with little target information loss; it is implemented easily by digital processor ADSP-TS201S with high performance and successfully used in an all directional IRST system. The experiments show the effectiveness of the detection performance.

Select this Article		The application of the multi-scale GVF model based on the B-spline lifting wavelet in medical images segmentation Juntao Xue, Zhengguang Liu, Hongwei Zhang, and Shucheng Wang Proc. SPIE 6279, 62793F (2007); http://dx.doi.org/10.1117/12.725334 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Snakes, or active contours, are used extensively in computer vision and image processing application, particularly to locate object boundaries. GVF (Gradient Vector Flow) model has resolved two key problems of the traditional deformable model. However, it still requires both the initial contour being close to the target and a large amount of computation. And it is difficult to process the cupped target edge. This paper analysis the characteristics of deformable model firstly, then proposed a new method based on B-spline lifting wavelet. Experimentations based on GVF model and MRI segmentation show that the proposed method is a good resolution to the initialization sensitivity and the large computation.

Select this Article		A general image processing algorithm demo and evaluation system for infrared imaging Hui-ming Qu, Qian Chen, Guo-hua Gu, and Xiu-bao Sui Proc. SPIE 6279, 62793G (2007); http://dx.doi.org/10.1117/12.725339 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Research of image processing algorithm is one of the key issues for infrared imager development. Nowadays, researchers of image processing algorithm and designers of infrared imager have presented many image processing algorithms. It is necessary to evaluate the practicability, real-time performance and adaptability of all these algorithms in advance of application. Based on virtual instrumental technology, a general demo and evaluation system for infrared image processing algorithms is developed. The system configuration is described in detail. The extendable property of this system made it suitable for various algorithms demo and evaluation. The vision impression of image processing algorithms demo is processed through labview programming. Designers can evaluate the performance of image processing algorithms in time. This system benefits designers to optimize their algorithms directly. Examples are applied in this system to prove its functions. Trial results show it is a useful tool for infrared imager developer and image processing algorithm designer.

Select this Article		An improved NAS-RIF algorithm for blind image restoration Ning Liu, Yanbin Jiang, and Shuntian Lou Proc. SPIE 6279, 62793H (2007); http://dx.doi.org/10.1117/12.725348 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image restoration is widely applied in many areas, but when operating on images with different scales for the representation of pixel intensity levels or low SNR, the traditional restoration algorithm lacks validity and induces noise amplification, ringing artifacts and poor convergent ability. In this paper, an improved NAS-RIF algorithm is proposed to overcome the shortcomings of the traditional algorithm. The improved algorithm proposes a new cost function which adds a space-adaptive regularization term and a disunity gain of the adaptive filter. In determining the support region, a pre-segmentation is used to form it close to the object in the image. Compared with the traditional algorithm, simulations show that the improved algorithm behaves better convergence, noise resistance and provides a better estimate of original image.

Select this Article		Enhancement of panoramic image resolution based on swift interpolation of Bezier surface Xiao Xiao, Guo-guang Yang, and Jian Bai Proc. SPIE 6279, 62793I (2007); http://dx.doi.org/10.1117/12.725352 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Panoramic annular lens project the view of the entire 360 degrees around the optical axis onto an annular plane based on the way of flat cylinder perspective. Due to the infinite depth of field and the linear mapping relationship between an object and an image, the panoramic imaging system plays important roles in the applications of robot vision, surveillance and virtual reality. An annular image needs to be unwrapped to conventional rectangular image without distortion, in which interpolation algorithm is necessary. Although cubic splines interpolation can enhance the resolution of unwrapped image, it occupies too much time to be applied in practices. This paper adopts interpolation method based on Bezier surface and proposes a swift interpolation algorithm for panoramic image, considering the characteristic of panoramic image. The result indicates that the resolution of the image is well enhanced compared with the image by cubic splines and bilinear interpolation. Meanwhile the time consumed is shortened up by 78% than the time consumed cubic interpolation.

Select this Article		A weighted least squares image matching based target tracking algorithm Xiaohu Zhang, Lichun Li, Xianwei Zhu, Yang Shang, and Qifeng Yu Proc. SPIE 6279, 62793J (2007); http://dx.doi.org/10.1117/12.725355 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Moving target tracking is a basic task in the processing of high speed photography. Despite its widely applications, Correlation tracking method can not adapt to the rotation and zoom of target and results in accumulation of tracking error. The Least Squares Image Matching(LSIM) method which is used in photogrammetry is introduced to moving target tracking, and a Weighted Least Squares Image Matching(WLSIM) based tracking algorithm is proposed. The WLSIM based algorithm sets weights according to the target's shape for the Least-Squares Image Matching Algorithm, as a result matching error produced by the background in the tracking window can be avoided. Experimental results are shown to demonstrate the robustness, efficiency and accuracy of the proposed algorithm.

Select this Article		Comparison of anamalous range image suppression methods of laser radar and combination of filter methods Chen Zhe, Li Qi, and Wang Qi Proc. SPIE 6279, 62793K (2007); http://dx.doi.org/10.1117/12.725359 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Laser radar could obtain the intensity image and range image synchronously, and the target is easily distinguished because of different range values, so the "Ladar" has abroad applications. However, in the range image proceeding, the target is always disturbed to illegible by speckle and random noise, how to retrain the noise as well as keep the image information becomes the crucial problem. This paper is based on the three filter methods: histogram, median, multiple level median, the methods are all based on the theory that the probability of range anomaly is far less than that of no anomaly, using the theory of stat sequence filter, could restrain the speckle and random noise very efficiency. The three methods have the different effect on the noise restraining and keeping edge from each other. To choose the methods, the contrast of each other method is made and the contrast and the characteristic have been got, the simulated result is obtained. This paper draws the conclusion that the histogram method has the best synthetically effect of the three methods, especially in the keeping edge. In the last, the filter methods are combined together to filter the raw image in different order and is found that the different order will make the effect different on the image; the reason is that the different order makes the initialization diverse for the filter methods. The result was showed in the end of the paper, while discussing the reason of the effect of the order.

Select this Article		Object-oriented information extraction technology from QuickBird pan-sharpened images Chunyan Zhou, Ping Wang, Zhenyong Zhang, Chengtao Qi, and Ying Wang Proc. SPIE 6279, 62793L (2007); http://dx.doi.org/10.1117/12.725360 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The high spatial resolution Remote Sensing image has richer information than the low or middle resolution image, such as structure and texture information. Traditional image classification technology which only uses spectral information of pixels is not suitable for the high resolution image. In order to make full use of the rich information, object-oriented thought is introduced into the high resolution information extraction. In contrast to traditional methods, the basic processing units of object oriented image analysis are image objects, and not single pixels. It could fully integrate spectral values and spatial information such as: shape, size and contextual relationship. The objective of this study is to extract kinds of information from QuickBird image of the urban area using the object-oriented information extraction approaches. Image processing includes geometric correction, HIS fusion, image segmentation and classification using the integration of fuzzy classification and the nearest neighbor (NN). 84.82% overall accuracy is achieved with this approach, while only 73.87% is achieved with traditional pixel-based method. It shows that object-oriented approach is promising in providing detailed and accurate information about the physical structure of urban areas from the high spatial image.

Select this Article		Superresolution reconstruction of images by weighted wavelet bicubic interpolation search algorithm You-shan Qu, Chuan-ping Bian, and Ying-cai Li Proc. SPIE 6279, 62793M (2007); http://dx.doi.org/10.1117/12.725362 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The variable relationship between the threshold of high-frequency extrapolation and the entropy of its correspondent reconstructed image in the Wavelet Bicubic Interpolation Algorithm is analyzed. The information entropy is used as a cost function and a Maximal Entropy Wavelet Bicubic Interpolation Search Algorithm is proposed. This algorithm can automatically search an extrapolation threshold to reconstruct an image with maximal entropy. Although the detail information of the reconstructed maximal entropy image is larger than its original image, it may introduce a lot of uncertain and incorrect information. In order to remedy this shortcoming of the proposed algorithm, a new cost function based on the old one is established. The new cost function can not only remedy the shortcoming of the entropy function as a cost function, but also a weight introduced in the new cost function can be adjusted to reconstruct different superresolution images to satisfy different practical requirements. Thus a Weighted Wavelet Bicubic Interpolation Search Algorithm is established. The experiment results prove that if the distribution of the processed images is close to the maximum likelihood distribution, a large weight will be selected to reconstruct a relative better superresolution image with better details, and if the distribution of the processed images is far from the maximum likelihood distribution, a little weight will be selected to reconstruct a relative better superresolution image with better visual effect. Therefore, the weight in the new algorithm can be selected from the requirements to satisfy different practical cases.

Select this Article		New 2D adaptive image thresholding method based on within and between cluster scatter Yunyan Zhou and Kuntao Yang Proc. SPIE 6279, 62793N (2007); http://dx.doi.org/10.1117/12.725364 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a novel image thresholding approach based on within and between cluster scatter of the 2D histogram is proposed. 2D Otsu's method not only utilizes the gray-level information of each pixel but also synthesizes its spatial correlation information within the neighborhood, so it is more valid in the threshoding. However, it doesn't take into account of the within cluster scatter, sometimes it can't reach the optimal thresholding validity. In this approach, within and between cluster scatter are integrated to improve the algorithm. The threshold vector that maximizes between cluster scatter and minimizes within cluster scatter at the same time is regarded as optimal threshold. In order to avoid exhaustively computing within cluster scatter, we simplify the threshold recognizing function via replacing within cluster scatter by the difference in total covariance and between cluster scatter. As the total covariance of a given image is a certain constant, the simple algorithm will decrease complexity of computation greatly without affecting the segmented result. Experimental results show that our proposed approach not only performs well and effectively but also is more robust when applied to noisy image.

Select this Article		Image blurring of narrow laser beam transfer in ocean and through wavy sea surface Min Xia, Kecheng Yang, Yi Zheng, and Jionghui Rao Proc. SPIE 6279, 62793O (2007); http://dx.doi.org/10.1117/12.725367 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In the detection of underwater object by air-born lidar, a narrow laser beam reflected by the sea bottom or the underwater target transfers in the ocean and refracted through the wavy sea surface, then received by the receiver carried by plane over the sea surface. Because of the scattering by the suspended particles and the effect of the wavy sea surface, the received signal will to some extent blurred, which will greatly decrease the image quality of the lidar system. Computer simulation by Monte Carlo method was employed to describe the process of narrow laser beam transferring in the ocean and refracted by the wavy sea surface. As the result, the intensity distribution on the receiver can be got as well as the property of image blurring after transferred thought the ocean water and refracted through the wavy sea surface. The relations between this property and the optical property of seawater, the wind speed above the sea surface were analyzed.

Select this Article		Double-channel on-line automatic fruit grading system based on computer vision Junxiong Zhang, Yi Xun, Wei Li, and Cong Zhang Proc. SPIE 6279, 62793P (2007); http://dx.doi.org/10.1117/12.725368 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The technology of fruit grading based on computer vision was studied and a double-channel on-line automatic grading system was built. The process of grading included fruit image acquiring, image processing and fruit tracking and separating. In the first section, a new approach of image grabbing by employing an asynchronous reset camera was presented. Three images of the different surfaces of each fruit would be collected by rolling the fruits when they passed through the image-capturing area. To acquire clear images, high-frequency fluorescent lamps supplied by three-phase alternating current were used to illuminate. In the image processing section, the diameter and a color model were used to identify the grade of the fruits. Fruits were graded into four grades by size, and two by color. Each fruit identified was tracked and separated by a novel algorithm which was realized with a PLC (Program Logic Controller). The whole grading system was tested with 1000 citrus. It could work stably when the grading capability was twelve citrus per second and the grading level was nine. The on-line grading results indicated that the accuracy of tracking and separating was higher than 99%, and the ultimate grading error was less than 3%.

Select this Article		Multiple facula targets recognition based on edge and region search Yang Shang, Xianwei Zhu, Qifeng Yu, Hongwei Han, and Xiaohu Zhang Proc. SPIE 6279, 62793Q (2007); http://dx.doi.org/10.1117/12.725373 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An algorithm of multiple facula targets recognition based on edge and region search in full field of a frame of image is presented. Firstly, the image is segmented by binarization and the burr around the targets is removed by morphology processing. Then every facula target's edge and region is found and numbered in turn. Experimental results on simulated images and real images are shown to validate the presented algorithm.

Select this Article		Automatic interpretation and precision detecting of target's axis in image sequences Xiaoli Hu, Yihui Xue, Sanxi Zhang, and Xiaobin Liu Proc. SPIE 6279, 62793R (2007); http://dx.doi.org/10.1117/12.725374 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Based on high speed photography video image sequences, target's motion parameters can be obtained by interpreting image sequences and calculating with interpretation results. The principle of traditional interpretation methods all obtained spatial coordinates of target's point based on target plane coordinates of target's point. If obtaining 3D attitude of rigid(spatial orientation of target's axis)with the information of two points' spatial coordinates, then the precision is difficult to reach the expected value. But if we interpret by extracting target's axis, then the interpretation precision and measuring precision can be advanced. In this paper interpretation technique of target's axis automatic detecting and tracking based on target's model and "WYSWYG" is proposed, detecting method of axis interpretation precision is introduced and the precision is analyzed.

Select this Article		Analysis of scannerless imaging lidar in large field of view condition Sining Li, Jinbo Liu, Qian Wang, and Qi Wang Proc. SPIE 6279, 62793S (2007); http://dx.doi.org/10.1117/12.725437 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Scannerless lidar has advantages of high frame-rate, large field of view (FOV) and miniaturization etc, it is especially valuable for military and aerospace engineering applications such as 3D vision, target recognition, autonomous machinery guidance and collision avoidance etc. In this paper, we analyzed the performance of scannerless imaging lidar, to investigate this, the overall system is divided into 6 modules according to various functions including transmitter, optical antenna, atmospheric transmission, target property, detector, data processor etc., whereas the physical processes of every module have been studied and corresponding mathematical models are also set up. The fundamental problem of imaging lidar system is numerical solution of lidar equation, however common lidar equation regards target as a point reflector with the assumption that back reflecting light is distributed uniformly in all directions in 2 solid angle, which is not for large FOV situation. In large FOV condition, the target can be regarded as a Lambertian reflector; the intensity of light back reflected from different part of the target is not same but follows the Lambert cosine law, so we make a modification for lidar equation, and finally all data from every module are coupled into lidar equation, through modified lidar equation calculation, the relationship between maximum acquisition range and emission power is discussed.

back to top

Poster Session: Femto-Attosecond Light and Photoelectron Sources

Select this Article		Analysis of the output impulse of PCSS triggered by femto-second laser pulse Zheng Jing, Tao Wang, Chi Ruan, Jingwei Wang, Hongchun Yang, Xiaoting Li, and Leixue Wu Proc. SPIE 6279, 62793T (2007); http://dx.doi.org/10.1117/12.725331 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this article different experiments are carried out to exam some key elements that influence the performance of PCSS (Photoconductive semiconductor switches). The experiments include the bias voltage over the switch, the trigger pulse energy and position. From the results we got the relationship among the elements and the output impulses. The bias voltage controls the output linearly; the rise of trigger energy increase the export voltage but when the energy get over 280J this trend slow down and the export voltage go to a fixed value; different positions change the export voltage and the peak value appears at the area near the cathode. The results were analyzed and explanations were given. From the discussion we give the evidences in helping to explain the linear mode, and point out an efficient way to use the laser energy for PCSS. Some tests methods are introduced and will be done in the future.

Select this Article		Self-starting 21-ps Ti:sapphire laser with high beam quality Weijun Ling, Yishan Wang, Wei Zhao, Jinrong Tian, Jiangfeng Zhu, and Zhiyi Wei Proc. SPIE 6279, 62793U (2007); http://dx.doi.org/10.1117/12.725718 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A self-starting all-solid-state picosecond (ps) laser was demonstrated. Different with a standard cavity design with semiconductor saturable-absorber mirror (SESAM), self-starting mode-locking was initiated by stretching the length of arm to reduce the beam spot, which shows the output beam possess higher beam quality than standard one. With a 10% output coupler, we achieved 1 W output power and 21 ps pulse duration at pump power of 4.5 W. High efficiency and high beam quality show the merit of the ps-laser.

Select this Article		Self-phase modulation of an ultra-short laser pulse from laser breakdown plasma Yongsheng Zhang, Lixin Yan, Guoxin Zheng, Lijun Wang, and Jingru Liu Proc. SPIE 6279, 62793V (2007); http://dx.doi.org/10.1117/12.725336 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The detailed dynamic of an atom in a laser field with strength comparable to the atomic electric field is rich in physics and potential applications. Laser-breakdown plasma-induced spectral shifting in supersonic rare gases jet has been investigated with a sub-picosecond KrF excimer laser focused to peak intensity in the region of 10¹⁵W/cm². A 1.4mm diameter gas jet target was used in the experiment to minimize the refraction of the laser beam and thus a well-defined focused region was obtained. The typical quasi-periodic spectral shifting structures for helium and argon have been measured at various gas densities. For gas densities below 1x10²⁰cm^-3,both spectral red-shift and blue-shift were observed, indicating the gas is partially ionized, in contrast to the predominantly blue shifted as the gas densities grows high and fully ionized. Compared to the other ultra-short pulse measurement methods, qualitative information about the pulse can be deduced by observing their spectrum after interacting with rare gas.

Select this Article		Self-starting mode-locked Cr: forsterite laser pumped by 1030 nm Yb: YAG laser Binbin Zhou, Peng Wang, Yu Cang, Jiaan Zhen, Zhiyi Wei, and Liangmin Chen Proc. SPIE 6279, 62793W (2007); http://dx.doi.org/10.1117/12.725338 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We report a self-starting mode-locked Cr:forsterite laser with 1030 nm Yb:YAG laser as the pump laser in this paper. Two chirped mirrors are used to provide the negative intracavity group-delay dispersion; the mode locking is initiated and stabilized by a semiconductor saturable-absorber mirror (SESAM). With absorbed power of 7W at 1030nm, stable femosecond laser pulses with average power of 202 mW were obtained at a repetition rate of 82.6 MHz, the autocorrelation measurement shows the typical pulse duration is about 29 fs.

Select this Article		Stabilization and phase control of femtosecond Ti:sapphire laser with a repetition rate of 90MHz Wei Zhang, Hainian Han, Peng Wang, and Zhiyi Wei Proc. SPIE 6279, 62793X (2007); http://dx.doi.org/10.1117/12.725341 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Carrier-enveloped phase controlled femtosecond laser has an important application in the absolute frequency measurement, which lead to a revolutionary progress in the frequency metrology. In this paper we will report a high stable optical frequency comb based on a 90MHz repetition rate Ti:sapphire laser, by using a photonic crystal fiber to broaden octave spanning spectrum and a self-reference technology to measure the offset frequency f_ceo, both the repetition rate f_rep and f_ceo are locked simultaneously to a cesium clock with phase lock loop (PLL) technology. For simultaneous stabilization of f_rep and f_ceo, two sets of phase-locked loop electronics are introduced to control separately the laser cavity length for f_rep with a PZT and the pump laser for f_ceo with an acoustic optics modulation (AOM) respectively. As the result, we stabilized the f_rep at a fluctuation within the order of Hz, and f_ceo is in the order of mHz, which support a frequency comb with an uncertainty of 10^-14.

Select this Article		Generation of 7-fs laser pulse and measurement of carrier-envelope phase by difference-frequency generation Yanying Zhao, Hainian Han, Peng Wang, Wei Zhang, and Zhiyi Wei Proc. SPIE 6279, 62793Y (2007); http://dx.doi.org/10.1117/12.725343 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An ultrabroaden spectrum covered from 600nm to 1000nm was directly generated from a self-designed femtosecond laser. The laser resonator consists in only three or four chirped mirrors and one output coupler, we measured the pulse duration is shorter than 7fs by compensating the dispersion outside the laser cavity, repetition rate of high as 160MHz was realized. As our best knowledge, this is the simplest laser configuration of generating the pulse of shorter than 10fs. To control the carrier-enveloped phase (CEP), we further used a PPLN crystal to generate the difference-frequency based on the ultrabroaden spectrum, a beat frequency with signal to noise ratio of 34dB was observed. Locking the beat frequency and the 160MHz repetiton rate to a Cs clock, it will enable us to realize a compact frequency comb with high repetition rate.

Select this Article		Compression and carrier-envelope phase control of 5fs laser pulse for driving attosecond pulse Jiangfeng Zhu, Peng Wang, Hainian Han, Hao Teng, and Zhiyi Wei Proc. SPIE 6279, 62793Z (2007); http://dx.doi.org/10.1117/12.725344 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A white light continuum of octave spanning was produced by self-phase modulation in a hollow-core fiber filled with noble gases at high pressure and subsequently compressed by a set of ultra-broadband chirped mirrors. Pulses as short as 5.1 fs with energy up to 400 J at a 1 kHz repetition rate were obtained. Based on the carrier-envelope phase (CEP) locking of the femtosecond oscillator and the spectral interference of the white light continuum between the white fundamental wave and the harmonic wave at the same wavelength, the CEP of 5.1 fs pulse can be further locked by modulating the pump laser through a slow loop. The intense, few-cycle laser pulses with a stable CEP will enable us to produce high-order harmonic X-ray laser by the interaction with a rare gas target, this may drive the individual attosecond pulse generation.

back to top

Poster Session: Pulsed X-ray Sources and Radiography

Select this Article		X-ray spectra from weakly ionized linear molybdenum plasma Haruo Obara, Eiichi Sato, Rudolf Germer, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, and Kazuyoshi Takayama Proc. SPIE 6279, 627940 (2007); http://dx.doi.org/10.1117/12.725347 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x-rays are produced by the discharging. The x-ray tube is a demountable triode with a trigger electrode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of weakly ionized linear plasma, consisting of molybdenum ions and electrons, around the fine target. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 17 kA. The K-series characteristic x-rays were clean and intense, and higher harmonic x-rays were not observed. The x-ray pulse widths were approximately 600 ns, and the time-integrated x-ray intensity had a value of approximately 2.0 mGy per pulse at 1.0 m from the x-ray source with a charging voltage of 50 kV.

Select this Article		High-sensitive radiography system utilizing a pulse x-ray generator and a night-vision CCD camera (MLX) Eiichi Sato, Michiaki Sagae, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Takashi Inoue, Akira Ogawa, Shigehiro Sato, Toshio Ichimaru, and Kazuyoshi Takayama Proc. SPIE 6279, 627941 (2007); http://dx.doi.org/10.1117/12.725351 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High-sensitive radiography system utilizing a kilohertz-range stroboscopic x-ray generator and a night-vision CCD camera (MLX) is described. The x-ray generator consists of the following major components: a main controller, a condenser unit with a Cockcroft-Walton circuit, and an x-ray tube unit in conjunction with a grid controller. The main condenser of about 500 nF in the unit is charged up to 100 kV by the circuit, and the electric charges in the condenser are discharged to the triode by the grid control circuit. The maximum tube current and the repetition rate are approximately 0.5 A and 50 kHz, respectively. The x-ray pulse width ranges from 0.01 to 1.0 ms, and the maximum shot number has a value of 32. At a charging voltage of 60 kV and a width of 1.0 ms, the x-ray intensity obtained without filtering was 6.04 Gy at 1.0 m per pulse. In radiography, an object is exposed by the pulse x-ray generator, and a radiogram is taken by an image intensifier. The image is intensified by the CCD camera, and a stop-motion image is stored by a flash memory device using a trigger delay device. The image quality was improved with increases in the x-ray duration, and a single-shot radiography was performed with durations of less than 1.0 ms.

back to top

Poster Session: Diagnosis of High-Temperature and High-Density Plasmas

Select this Article		Investigation of interaction of the plasma clouds forming as a result of two laser target irradiation V. I. Annenkov, A. V. Bessarab, G. A. Bondarenko, G. V. Dolgoleva, G. G. Feldman, V. A. Krotov, V. P. Kovalenko, A. V. Kunin, V. B. Lebedev, I. N. Nikitin, E. A. Novikova, A. I. Panov, I. V. Sobolev, S. S. Sokolov, V. A. Starodubtsev, et al. Proc. SPIE 6279, 627942 (2007); http://dx.doi.org/10.1117/12.725357 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The results of investigation of two plasma clouds interaction appearing at the laser irradiation of two different targets in background gas atmosphere on the MKV-4 facility of the "Iskra-5" has been described. The experimental data are compared with the results of the theoretical simulation.

Select this Article		Experimental study on the flame behaviors of premixed methane/air mixture in horizontal rectangular ducts Dongliang Chen, Jinhua Sun, Sining Chen, Yi Liu, and Guanquan Chu Proc. SPIE 6279, 627943 (2007); http://dx.doi.org/10.1117/12.725361 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In order to explore the flame propagation characteristics and tulip flame formation mechanism of premixed methane/air mixture in horizontal rectangular ducts, the techniques of Schlieren and high-speed video camera are used to study the flame behaviors of the premixed gases in a closed duct and opened one respectively, and the propagation characteristics in both cases and the formation mechanism of the tulip flame are analyzed. The results show that, the propagation flame in a closed duct is prior to form a tulip flame structure than that in an opened duct, and the tulip flame structure formation in a closed duct is related to the flame propagation velocity decrease. The sharp decrease of the flame propagation velocity is one of the reasons to the tulip flame formation, and the decrease of the flame propagation velocity is due to the decrease of the burned product flow velocity mainly.

Select this Article		Optics-ammunition mechanism of plasma radiation inspired by exploding wires blasting in inert gases Xuan-ke Zhao, Qing-wu Zhao, Qing-hua Zhang, and Lian-fen Wang Proc. SPIE 6279, 627944 (2007); http://dx.doi.org/10.1117/12.725363 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We studied a new optics-ammunition mechanism by an adiabatic heating model of exploding wires on strong pulsed current and a model of shock waves inspired by exploding wires blasting in inert gases. A Pspice simulation code for engineering applications and an improved MHD (Magnetohydrodynamics) computation code for physics research have developed in this paper. The computation results indicate that, firstly, plasma radiation intensity increased by Machnumber of shock waves, and in all insert gases, argon's Mach-number of shock waves is highest. Secondly, silver is the best in common metal materials, and the exploding time and current peak is about linear with the number of wires. Thirdly, the parameters of wire including the diameter, length and number will influence the exploding performance deeply; Fourthly, Pspice computation is an experiential method, but the result has direct guiding sense for engineering design. Fifthly, the improved 1D single temperature MHD model can be used in multi-wire paralleled electricity exploding computation very well, and computation results agree with the known experiment data and are important to the study of strong pulsed IR optics-ammunition.

Select this Article		Optical imaging system for wire array Z-pinch on "Qiangguang-I" Liang Sheng, Min Lv, Kui-lu Wang, Ai-ci Qiu, Dong-wei Hei, Meng-tong Qiu, Fu-li Wei, Yuan Yuan, and Pei-wei Wang Proc. SPIE 6279, 627945 (2007); http://dx.doi.org/10.1117/12.725366 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A time-resolved optical imaging system is developed for "Qiangguang-I" generator to diagnose the early stage of wire array Z-pinch. The optical imaging system is consisted by several independent modules. Each module includes a set of object lens, an image intensifier, a set of relay lens and a CCD camera. The peak response of the system is at 439 nm. The temporal resolution of the system is about 5ns, and the equivalent spatial resolution on the object plane is 6.5 lp/mm when MTF=0.05. A series of images of 12mm diameter 32x5m tungsten wire array obtained by the system are shown in this paper. We find that in the 32x5 m wire array experiments on "Qiangguang-I", from the implosion start to 60% of implosion time, the behavior of single wire is dominant. The implosion time is (113±7) ns and the ratio of acceleration time to implosion time t_a/t_imp is about 0.60~0.75. The trailing mass distribution and the m=1 mode instability after the stagnation phase are also observed in our experiments.

back to top

Poster Session: Ultrafast Lasers and Applications

Select this Article		Generation of short electrical pulses by photoconductive semiconductor switches triggered with a high-power laser diode Tong-Yi Zhang, Shun-Xiang Shi, and Wei Zhao Proc. SPIE 6279, 627946 (2007); http://dx.doi.org/10.1117/12.725369 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Microstrip line pulse generators based on gallium arsenide (GaAs) photoconductive semiconductor switches have been fabricated and tested experimentally. The GaAs photoconductive semiconductor switches were optically triggered with a 70 W, 85 ns duration (FWHM) high power laser diode. Short electrical pulses have been obtained and reported with practical applications emphasized. The risetimes and the durations of the output electric pulses can be less than 2 ns and 6 ns, respectively, which are in remarkable contrast to the 20 ns risetimes and the 85 ns durations of the activating optical pulses.

Select this Article		Theoretical and numerical investigations of fused silica modification using ultrafast double-pulses Qing Liu, Jianjun Wang, Guanghua Cheng, Junjun Chen, Feifei Liu, and Changqing Liu Proc. SPIE 6279, 627947 (2007); http://dx.doi.org/10.1117/12.725370 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We study the mechanisms of ultrafast free-electron generation in laser-irradiated dielectrics (fused silica). The evolution of the free-electron density in the conduction band of dielectrics irradiated by ultrafast double-pulses laser is calculated. The effects of the avalanche ionization is calculated with the recently introduced multiple rate equation, which keeps track of the energy distribution of the free electrons, while maintaining the conceptual and analytic simplicity of the standard rate equation. Using temporally shaped pulse trains with picosecond separation leads to a significant improvement in the quality of ultrafast laser micro-structuring of dielectrics. The evolution of the free-electron density in fused silica irradiated by tightly focused 100 fs laser double-pulses at a center wavelength of 800 nm are numerically investigated to study the role of nonlinear photo-ionization and avalanche ionization processes in free electron generation. The role of impact ionization as compared to photoionization is analyzed.

Select this Article		Fast photomultiplier tube gating system for underwater laser detector Xuanhua Lei, Kecheng Yang, Jionghui Rao, Xiaohui Zhang, Min Xia, Yi Zheng, and Wei Li Proc. SPIE 6279, 627948 (2007); http://dx.doi.org/10.1117/12.725375 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Laser will attenuate during its propagation in water and also be backward scattered by water when it is used to detect bubbles in the ocean. Meanwhile backward scattering intensity of the bubbles is feeble, its dynamic range reaches to the order of 6, which saturates PMT and its post-treatment circuit. Timely gating system is used to solve the problem. The system contains pulsed laser and gating PMT receiver. The wavelength of the laser is 532nm, with pulse width of several nanometers. Its operational delay is matched with the time period between laser traveling forward and back after scattered by the target. By doing this, the light scattered by other object is eliminated, dynamic range of the signal reduces, and consequently SNR increases. In order to avoid Signal Induced Noise(SIN), we choose PMT R1333 having no HA coating. TTL logical level, which is used as gating signal, controls the first dynode voltage of PMT to implement gating. Gating speed is about 100ns, of which the width is tunable. By carefully designing the electronic system, SNR is eliminated to a level as low as possible, and the output signal of PMT is fast integrated in order to reduce the influences of signal induced by opening the gate.

Select this Article		Laser induced defect damage on optical thin film ShiGang Wu, ZhiLin Xia, JianDa Shao, Kui Yi, and ZhengXiu Fan Proc. SPIE 6279, 627949 (2007); http://dx.doi.org/10.1117/12.725377 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Interaction of laser irradiation with coating defects is studied in this paper. For microdefect, sphere impurity defect model is employed to explain the breakdown process of optical thin film. For sub-microdefect, avalanche ionization by nonlinear absorption is main way to lead thin film breakdown. To testify the effect of defect on the damage of thin film, HfO₂ thin films were deposited by the electron-beam evaporation method. The weak absorption and laser induced damage threshold (LIDT) of thin film samples were measured, the damage morphology and defect density of samples were also mapped by Nomarski microscope. These results indicated that the kind of damage morphology of thin film is found to be typically defects initiated. The damage of every sample originates from defects and the damage enlarges from the point of defects. It was also found that the absorption of the films would increase and the LIDT would decrease with the increase of defect density.

Select this Article		Research on the stable state distribution of femetosecond pulses optical soliton communication system Aihan Yin, Qingmiao Zhang, Aiyan Zhan, and Wang Bin Proc. SPIE 6279, 62794A (2007); http://dx.doi.org/10.1117/12.725379 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract With the high-speeding development of the ultrashort laser pulses techniques, the stability of the soliton propagating in the dispersion-shift fiber has been becoming the topic in high speed optical communication system. From the nonlinear Schrdinger equation, in this paper we discuss a quasi soliton specific solution without distortion which has the stable propagating property, then simulate the waveform about these quasi solitons numerically, and more, by modifying the structure parameters of the fiber the width of these quasi soliton pulse can be adjusted and the soliton communication system can be optimized finally.

Select this Article		Laser-induced acoustic landmine detection with YAG and erbium fiber laser Changqing Cao, Xiaodong Zeng, Yuying An, Juncheng Xu, and Yili Zheng Proc. SPIE 6279, 62794B (2007); http://dx.doi.org/10.1117/12.725382 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. An important issue in ALD is the acoustic excitation of the soil. Laser excitation is promising for complete standoff detection using lasers for excitation and monitoring. Our method is based on a YAG laser at 1.06 um not He-Ne laser or loudspeaker with acoustic excitation and on an erbium fiber laser at 1.54 um not microphone with LDV detection. An analysis is given to show the potential and the inherent limitations of the technique. In the present paper we have tried to answer two questions on locating landmines: (1) too many false alarm; (2) plastic landmine. The answer to the first question is the LDV with an erbium fiber laser at 1.54 um. The second answer is YAG laser at 1.06 um induce acoustic.

Select this Article		Compensation of high-order phase distortions in chirped-pulse amplification system Bing Zhou, Yong-Liang Jiang, Yu-xin Leng, Xiao-Wei Chen, Ru-Xin Li, and Zhi-Zhan Xu Proc. SPIE 6279, 62794C (2007); http://dx.doi.org/10.1117/12.725383 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Chirped-pulse amplification (CPA) technique has been widely used to generate ultra-intense femto-second pulses. In this scheme the seed pulses from an oscillator are stretched before amplification. The stretched pulses can support more energy extraction and effectively decrease the nonlinear effects in the gain media. The subsequent amplification in a CPA chain will result in a broadening of the output compressed pulses in temporal domain due to the gain narrowing and uncompensated phase distortions. In our experiment, using spectral modulation and phase pre-compensation system (Acoustic-Optics Programmable Dispersive Filter) between the oscillator and the stretcher, the effects of gain narrowing and high-order dispersions on the pulse duration in kHz chirped-pulse amplification system have been pre-compensated, and the spectral FWHM is expanded from 30nm to 50nm. The effects of GDD, TOD and FOD were investigated by scanning the four dispersion parameters respectively. By pre-compensating the high-order phase distortions with the phase measured by SPIDER, we successfully optimize the output duration from 51fs to 30fs, which is 1.07 times Fourier-transform-limitation.

Select this Article		Multi-pulse operation of Yb³⁺-doped fiber mode-locked laser L. Zh. Yang, Y. C. Wang, G. F. Chen, Y. Sh. Wang, and W. Zhao Proc. SPIE 6279, 62794D (2007); http://dx.doi.org/10.1117/12.725385 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The multi-pulse operation of the Yb³⁺-doped fiber mode-locked laser with a polarization sensitive isolator and two polarization controllers is reported. Dual- and triple-pulse of the Yb³⁺-doped fiber mode-locked laser in the normal dispersion are achieved as the pumping power is increased. The fiber laser can achieve different multi-pulse outputs by adjusting the polarization controllers or increasing the pump power. The results show that over-driving of the fast artificial saturable absorber induced the generation of the multi-pulse.

Select this Article		Numerical study on the propagating performance of super-Gaussian ultra-short optical pulse Shuqin Guo, Wensheng An, and Guangxin Zhu Proc. SPIE 6279, 62794E (2007); http://dx.doi.org/10.1117/12.725387 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract When an optical pulse with super-Gaussian shape is transmitted in fiber, it will gradually evolve to Gaussian function shape under suffered all kinds of effects, such as group velocity dispersion (GVD), third order dispersion (TOD), forth order dispersion (FOD), and nonlinear effects. An interesting phenomenon is observed, that is, TOD will transfer energy of super-Gaussian pulse from one half to another within total flat top, but TOD will split Gaussian optical pulse and bring strong oscillation structure in the edge of pulse. Corresponding to frequency domain, super-Gaussian pulse has two evident slide slobs arranged in both sides of main peak, but TOD can make slobs fade away and transform frequency spectral to Gaussian function shape. In a densely dispersion managed (DDM) fiber system, the propagation performance of super Gaussian pulse with sub-picosecond pulse width is investigated. From clear eye-diagram of propagating over 1000 km, we can conclude that the DDM fiber system is very suitable for super Gaussian optical pulse transmission under low system power condition.

Select this Article		Near-field optical characteristics of sub-wavelength grating irradiated by ultra-short optical pulse Pinghe Zhou, Ying Guo, Feng Pan, Shaohua Wang, Shijie Liu, Zhengxiu Fan, and Jianda Shao Proc. SPIE 6279, 62794F (2007); http://dx.doi.org/10.1117/12.725388 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We present a method for near-field analysis of ultra-short optical pulse propagation in the sub-wavelength grating based on the integration of Fourier spectrum decomposition and Fourier modal method. By using this method, near-field optical distribution within a high-efficiency reflective grating based on total internal reflection (TIR) is calculated as the irradiation source is a 200fs optical pulse with central wavelength of 1053nm. Electric field enhancement within the TIR grating is analyzed for both TE- and TM-polarized pulses. Methods of controlling the peak intensity in the grating ridge are also presented.

Select this Article		Passive Q-switched fiber laser with SESAM in ytterbium-doped double-clad fiber Cun-xiao Gao, Wei Zhao, Yi-shan Wang, Shao-lan Zhu, Guo-fu Chen, and Yong-gang Wang Proc. SPIE 6279, 62794G (2007); http://dx.doi.org/10.1117/12.725390 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A passively Q-switched ytterbium-doped double-clad fiber laser with SESAM as a saturable absorber is demonstrated experimentally. This system showed up to 18.7mW output power, up to 29.4 kHz repetition rate, a maximum pulse energy of 0.636J and a minimum pulse duration of 3.148 s. The characteristics of pulse were investigated, and the theoretical analysis agree well with the experimental results.

Select this Article		Experimental study on laser ablating different materials in atmosphere Jing Li and Zhiping Tang Proc. SPIE 6279, 62794H (2007); http://dx.doi.org/10.1117/12.725391 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In order to investigate the laser ablation propulsion property of different materials in atmosphere, experiments are conducted, with a Nd:YAG passive Q-switch solid laser (single pulse energy 66mJ, pulse width 70ns) as energy source, black rubber, gray PVC, brass and SiC as testing materials. As results, the momentum coupling coefficients of the measured materials rise first and then fall with the increase of laser power density, which agrees with the observation of aluminum in vacuum. Among the tested materials gray PVC shows the lowest plasma ignition threshold, which is 0.86x10⁸w/cm², and highest momentum coupling coefficient, which is 11.83dyne/w.

back to top

Poster Session: High-Speed Holography and Interferometer

Select this Article		A differential interferometer with the four-focus imaging system Guang-hua Chen, Ze-ren Li, and Shou-xian Liu Proc. SPIE 6279, 62794I (2007); http://dx.doi.org/10.1117/12.725392 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new type of differential interferometer was created by placing the ring cavity of a cyclic lateral shearing interferometer between two lenses of a four-focus imaging system. The four-focus system is slightly defocused by adding an offset between the object plane and the front focal plane of the first lens. The shear distance of images varies directly as both the offset and the shear distance of the cyclic interferometer. The spatial carrier frequency of fringes varies directly as the shear distance of the cyclic interferometer, but it is independent of the offset. Thus the dependence between the carrier frequency and the shear distance of images is broken and it's possible to adjust them respectively. Furthermore, this differential interferometer is also very stable, which is important when vibrations can't be avoided in experiments. The interferometer has been applied to diagnostics of plasma with large density gradient.

Select this Article		A new real-time surface profile measurement using a sinusoidal phase modulating interferometry Guotian He, Xiangzhao Wang, Dailin Li, and Jianmin Hu Proc. SPIE 6279, 62794J (2007); http://dx.doi.org/10.1117/12.725393 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, a sinusoidal phase modulating interferometer has been proposed to realize real-time surface profile measurement. And its operation principle has been analyzed theoretically. By analyzing the interference signal through the signal processing circuit, the displacement of each point on the surface can be obtained. The experimental results by using this interferometer to measure a glass plate show the maximum root-mean-square is 5.2nm, and the displacement resolution is up to 5x10^-3nm.This method proposed in this paper avoids the complex phase demodulation by computer, has high measurement accuracy, and can be used in the noise circumstance.

Select this Article		Research of transient flow field real time interferogram acquisition system Jiao Liang, Yongying Yang, Dong Liu, Yongmo Zhuo, Jianhua Hui, and Junmiao Weng Proc. SPIE 6279, 62794K (2007); http://dx.doi.org/10.1117/12.725420 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes a novel synchronous control system of high speed imaging, which combines a common path interferometer system modulated by the space phase. The system can continuously grab multiple frame interferograms, which contain transient flow field distortion. The study of this system will provide a fire-new means for the research of aerodynamics. The light source of the system is Nd: YLF semiconductor pump solid pulsed laser of which wavelength is 1053 nanometers. The laser pulse width is less than 30 nanoseconds, far less than the exposure time of the camera shutter. Thus the laser pulse can freeze the flow field within several dozen nanoseconds and catch the biggish change of turbulent flow. The pulsed laser beam containing the information of turbulent flow enters a cyclical radial shearing interferometer. The emergent lights, being respectively contracted and expanded, re-combine and form fringe pattern in high space frequency, modulated with a definite carrier frequency. The fringe pattern is formed on the high speed CMOS camera at last. An accurate short time delay circuit is provided for synchronization matching of the pulsed laser and camera exposure. The speed of image acquisition in full pixels with 1280×1024 can reach 450 frames per second. This interferogram acquisition system with compact configuration and strong anti-disturbance capability, has successfully grabbed clear transient interferograms that provided reliable image information for follow-up image processing and flow field density calculating.

Select this Article		Research on optical interferometric communication frequency characteristic test and matching method Li-Li Guo, Yi Wang, and Ke-jia Wang Proc. SPIE 6279, 62794L (2007); http://dx.doi.org/10.1117/12.725424 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper proposes a laser light source and component frequency characteristic test and match design scheme based on space laser communication of optical interferometric heterodyne detection. The scheme utilizes dual phase-shifted fiber gratings to modulate frequency when the interferometric light of different frequency pass photoconductive photodetector weeny light heterodyne frequency switch highly electronic frequency and proceed to frequency response test and matching. We can proceed to match design of total system optical frequency characteristic according as component frequency characteristic matching adjustment. Compared with conventional scheme that the variety of regulable optical cavity length obtains beat frequency signal in the photoconductive photodetector, the scheme can proceed to exceed broad band frequency response characteristic test to photoconductive photodetector and total communication system without additional calibrate light source and the scheme possess quantitative control and narrow line breadth of laser signal less polarization so that highly precision of test and distinguishability. The scheme significantly improves anti-jamming performance of optical communication system and advances a novel method in the test and matching design of optical communication laser frequency characteristic.

Select this Article		Observation and research of chip formation and efflux by high speed hard cutting Xianli Liu, Fugang Yan, Yu Wang, Yiwen Wang, Hongmin Pen, and Tao Chen Proc. SPIE 6279, 62794M (2007); http://dx.doi.org/10.1117/12.725427 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper observed the chip forming and effusing process when high speed hard turning hardened steel using PCBN tools under two-dimensional longitudinal turning and transverse turning by high-speed photography, and obtained the chip formation and efflux states with different cutting edge preparation and parameters. The experiment results showed that the sharp-edged tool was useful for chip forming, but strength of its edge is low and the tool life is short, and that the tool has longer life under the chamfered edge, but too small or too large cutting thickness goes against the chip forming and effusing.

Select this Article		An adaptive mean shift particle filter for moving objects tracking Xun Wang, Yufei Zha, and Duyan Bi Proc. SPIE 6279, 62794N (2007); http://dx.doi.org/10.1117/12.725431 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, we integrate mean shift algorithm into the particle filter as the proposal distribution, and adaptively modify the tracking step according to the process of mean shift algorithm. It can be used through the searching for the most matching region with the feature, such as color, texture, etc, which should first be drawn from the targets. Experiments show that it is an efficient and powerful method for tracking fast moving objects in clutter even with occlusions.

Select this Article		Moving airplane real-time detecting based on lifting wavelets Jianhua Wu, Wenhua Qiu, and Ping Wang Proc. SPIE 6279, 62794O (2007); http://dx.doi.org/10.1117/12.725435 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Moving objects detecting is one of the most important tasks in a lot of fields like robot vision, video information processing. A moving plane detecting method based on lifting-wavelets is introduced in this paper in order to improve the performance in the aspects of nicety and real-time. In the detecting process, we have taken full advantages of the characteristics of multi-resolution and the merit that lifting frame can be designed in time and frequency fields. Experimental results show that this method can increase the detecting efficiency effectively in different cases where the background is complicated and artificial objects are greatly different. The detecting capabilities would not be affected by the condition of moving objects. This method has good robustness and can remove noise well at the same time.

Select this Article		Research on applications of optical wavelet transform in high-speed photograph Tao Wang, Dongmei Li, Chunkuang Tao, and Haiquan Shi Proc. SPIE 6279, 62794P (2007); http://dx.doi.org/10.1117/12.725438 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Image and data are always needed to be processed and analyzed at real time during high-speed photograph, so high processing speed is required. As the optical wavelet transform utilizes the parallel computation of optical elements, it has a high transform speed. Hence it can be used for image processing and analysis during high-speed photograph. The light-path structure and principle of optical wavelet transform is introduced in this paper. It is realized by using 4f optical information processing system. And the methods for realizing pattern recognition, image feature extraction, image edge enhancement etc. are given. Specially, the requirements on light source, light-path structure, optical elements and filter of optical system are analyzed when optical wavelet transform is used for image compression. And some improved measurements are put forward according to present problems. Firstly, the merits of using white light information processing system for image compression is analyzed. Secondly, adopt liquid crystal light valve and spatial light modulator to strengthen flexibility and practicability. Thirdly, the method of determining focuses of lens and how to use Talbot effect to locate the object plane and spectrum plane are given. Finally, the use of reflecting 4f system is put forward to decrease chromatic aberration and noise in optical wavelet transform. And we have obtained some experimental results which are good for further research.

Select this Article		Dynamic monitoring studies for high speed mechanical manufacturing process Yonghong Zhang, Lihua Wang, Qi Wu, and Dejin Hu Proc. SPIE 6279, 62794Q (2007); http://dx.doi.org/10.1117/12.725442 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The high-speed image sampling based on CCD camera was used monitoring abrasive machining and boring machining respectively in this paper. The two monitoring system organization and their principles of operation were introduced in detail. The transient images of grinding wheel or boring cutter nose were sampled at certain positions, which were detected by sensors. Mathematical derivation was analyzed and gave relationship of influencing factors. From some experiments, it can be seen that the monitoring method based on CCD camera is effective and real-time.

Select this Article		Free-surface velocity measurements using an optically recording velocity interferometer Jian-xin Lu, Zhao Wang, Jing Liang, Yu-sheng Shan, Chuang-zhi Zhou, Yi-huai Xiang, Ze Lu, and Xiu-zhang Tang Proc. SPIE 6279, 62794R (2007); http://dx.doi.org/10.1117/12.725447 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An optically recording velocity interferometer system (ORVIS) was developed for the free-surface velocity measurements in the equation of state experiments. The time history of free-surface velocity and the particle velocity in laser deduced shockwaves experiments can be recorded by the electronic streak camera in ORVIS. The interference fringe shifts recorded by the ORVIS is proportional to the Doppler shift of a laser beam induced by being reflected from the back suface of the monitored target. In the experiments, ORVIS got an 179 ps time resolution, and a higher time resolution could be got by minimizing the delay time. The equation of state experiments were carried out on the high power excimer laser system called "Heaven I", the velocity of iron and aluminium was researched.

Select this Article		Study of high speed photography measuring instrument Zhijun Zhang, Jiyu Sun, and Keyong Wu Proc. SPIE 6279, 62794S (2007); http://dx.doi.org/10.1117/12.725452 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High speed photograph measuring instrument is mainly used to measure and track the exterior ballistics, which can measure the flying position of the missile in the initial phase and trajectory. A new high speed photograph measuring instrument is presented in this paper. High speed photography measuring system records the parameters of object real-time, and then acquires the flying position and trajectory data of the missile in the initial phase. The detection distance of high speed photography is more than 4.5km, and the least detection distance is 450m, under the condition of well-balanced angular velocity and angular acceleration, program pilot track error less than 5'. This instrument also can measure and record the flying trail and trajectory parameters of plane's aero naval missile.

Select this Article		A servo-control system for detecting micro-displacement based on interferometry Jianhua Hui, Yongying Yang, Jiao Liang, and Chunhua Lu Proc. SPIE 6279, 62794T (2007); http://dx.doi.org/10.1117/12.725456 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Enhancing the measurement precision of the micro-displacement has become a significant trend of modern technology. This paper describes a servo-control system that can detect the displacement up to the order of nanometer on the basis of interference and resonance intensifying. The micro-displacement variance of a sample would cause the amplitude change of the microprobe, vibrating at the resonance frequency. By a point-diffraction-interference system, the amplitude change can converted to electrical signal after the photodiode detector. Then, this signal is sent to the feedback control system with PID model. Amplified by the high-voltage circuit, the feedback signal drives the piezoelectric crystal under the sample working stage to flex, keeping the distance constant between the microprobe and the sample. The circuit design possesses compact structure, good noise resistance and high stability. Apply this system to an atomic force microscope (AFM) to scan the sample surface coating aluminum fluoride. The results show that under the condition of 100 kHz resonance frequency, the image quality of sample's microscale topography with this servo-control system is evidently better than that with open-loop system. The operation only costs dozens of seconds to finish scanning 400×400 points and the precision is better than the order of nanometer.

Select this Article		Moving object detection under complex background using radial basis function neural network Zuomei Lai, Jingru Wang, and Qiheng Zhang Proc. SPIE 6279, 62794U (2007); http://dx.doi.org/10.1117/12.725457 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It is well known that moving object detection under complex background becomes more difficult because of moving cameras. According to the fact that background and objects have different motion, the moving scene can be decomposed into different regions with respect to their motion by means of a radial basis function(RBF) learning scheme. After global background motion compensation, five-dimensional (5-D) feature vectors include pixel intensities, current pixel coordinates and pixel dense optical flow field extracted from image sequences are treated as the inputs of the RBF network. The learning algorithm for the network minimizes a cost function derived from the Bayesian estimation theory. Each output unit of the network is associated to a moving object. Experimental results indicate the algorithm's validity after many complex sequences are tested.

Select this Article		The measurement of micro-topography surface based on wave cutting interference theory Mei Hui and Nian-mao Deng Proc. SPIE 6279, 62794V (2007); http://dx.doi.org/10.1117/12.725460 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper proposes the measurement of micro-topography surface based on wave cutting interference theory. This wave cutting interference system realized the differential cutting and complex polarization with beam splitter polarize prism. Math model is established based on matrix analysis. The phase distribution is obtained with equation between intensity and phase from the figure of the light intensity information, the value of micro-topography surface is obtained after data manipulation. Some technical difficulties existed in the surface microscopy are analyzed and solved.

Select this Article		Source rock maturity study by capillary tube interferometer Ailing Yang, Wendong Li, Junyu Dong, and Jinliang Zhang Proc. SPIE 6279, 62794W (2007); http://dx.doi.org/10.1117/12.725566 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The mechanism of capillary tube interferometer is expected to be two-beam interference by ray tracing. A computer program to simulate the interference fringe pattern was established. By comparing the simulated fringe pattern and experimental fringe pattern, the refractive index of the liquid can be given when the two fringes coincide best. The results of this method are very near the Abbe refratometer. In the first time, the refractive indices of the low transparent extraction of source rocks were measured by capillary tube interferometer. A curve between the refractive indices of the diluted extraction of source rocks and corresponding vitrinite reflectance Ro was established. When Ro is in the range of 0.36-1.25, the refractive indices of the extraction increase with Ro, or the maturity of the source rocks. Good correlation was observed between the refractive indices and vitrinite reflectance Ro. The refractive index of the extraction of source rock is valuable for determining the degree of maturity of source rock. This technique is promising to measure the refractive indices of low transparent liquids and could be used to estimate the maturity of source rock.

Select this Article		Applications of High-speed motion analysis system on Solid Rocket Motor (SRM) Yang Liu, Guo-qiang He, Jiang Li, Pei-jin Liu, and Jian Chen Proc. SPIE 6279, 62794X (2007); http://dx.doi.org/10.1117/12.725568 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High-speed motion analysis system could record images up to 12,000fps and analyzed with the image processing system. The system stored data and images directly in electronic memory convenient for managing and analyzing. The high-speed motion analysis system and the X-ray radiography system were established the high-speed real-time X-ray radiography system, which could diagnose and measure the dynamic and high-speed process in opaque. The image processing software was developed for improve quality of the original image for acquiring more precise information. The typical applications of high-speed motion analysis system on solid rocket motor (SRM) were introduced in the paper. The research of anomalous combustion of solid propellant grain with defects, real-time measurement experiment of insulator eroding, explosion incision process of motor, structure and wave character of plume during the process of ignition and flameout, measurement of end burning of solid propellant, measurement of flame front and compatibility between airplane and missile during the missile launching were carried out using high-speed motion analysis system. The significative results were achieved through the research. Aim at application of high-speed motion analysis system on solid rocket motor, the key problem, such as motor vibrancy, electrical source instability, geometry aberrance, and yawp disturbance, which damaged the image quality, was solved. The image processing software was developed which improved the capability of measuring the characteristic of image. The experimental results showed that the system was a powerful facility to study instantaneous and high-speed process in solid rocket motor. With the development of the image processing technique, the capability of high-speed motion analysis system was enhanced.

Select this Article		High-speed phase shifting profilometry with dual-frequency digital projection grating pattern Yanming Chen, Yuming He, Eryi Hu, and Hongmao Zhu Proc. SPIE 6279, 62794Y (2007); http://dx.doi.org/10.1117/12.725569 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An investigation of optical shape and profile measurement technique with respect to dual-frequency digital projection grating pattern is presented in this paper. Two gratings with different frequencies are respectively projected onto an object for the extension of the unambiguity range. And then, grating patterns which are deformed according to the object shape are acquired by a CCD camera. The 3D shape of object surface is reconstructed by using dual-frequency-combination phase-shifting profilometry (PSP) algorithm which is especially presented. Several advantages of using new algorithm instead of other traditional approaches are adequately discussed in practical measurement. Comparing to either conventional PSP or dual frequency PSP, dual-frequency-combination PSP has speediness advantage because of no phase unwrapping process and other additive processes. Furthermore, the analysis proves that the variance of phase in dual-frequency-combination PSP is much steadier than that in dual-frequency PSP. Finally experimental results demonstrated the feasibility of this technique for high-speed surface profile measurement.

Select this Article		Projected fringe profilometry of a high speed moving object using a time delay and integration imaging Yanming Chen, Yuming He, Eryi Hu, and Changhong Ai Proc. SPIE 6279, 62794Z (2007); http://dx.doi.org/10.1117/12.725571 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel technique is presented for measurement of surface profile, dynamic inspection of surface quality and nondestructive detection of a motion object at highly constant speed in this paper. In practice, a sinusoidal grating pattern with a common LCD projector is projected onto a moving object. Then, grating patterns which are deformed according to the object shape are acquired by a CCD camera operating in time delay and integration (TDI) mode. When the charges in TDI camera are shifted row by row at a specified speed which is the same as the object speed, a clear and bright image is easily obtained. Because of this advantage in the application of TDI camera, it is proved to be an effective and straightforward approach to avoid blurred image in high speed 3D projection grating patterns profilometry. In our experiment, Fourier transform algorithm is used for projected fringe profilometry. Upon that, absolute 3D surface profile is perfectly achieved. Finally, several factors which will induce measurement errors are respectively discussed, such as the speed disharmony between the object and TDI charges transfer and orientation disorder between the fringe pattern and motion object.

back to top

Poster Session: High-Speed Video Technique

Select this Article		Design of underwater video attached to buoy for observing shallow water substrate Y. Dingtian, C. Wenxi, and P. Delu Proc. SPIE 6279, 627950 (2007); http://dx.doi.org/10.1117/12.725572 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Knowledge of shallow water substrate is very important for protection and management of coastal ecosystem. Traditional methods for observing shallow water substrate was by sending diver to photography and recorded with eye, which was laborious and money taking. In order to obtain the easier way to study the shallow water substrate, an underwater video system was designed. Underwater video sensor, optical sensor, sonar sensor, tiltometer, GPS system, and ascending and descending system were all attached to the buoy system, and data was gathered and processed by the computer on the ship. The obtained data could be used for analyzing substrate type, activity of benthos and ground truth data for satellite remote sensing.

Select this Article		Motion detection and estimation in low-level-light video sequence Si Tian, Benkang Chang, Youtang Gao, Yafeng Qiu, Jianliang Qiao, and Rongguo Fu Proc. SPIE 6279, 627951 (2007); http://dx.doi.org/10.1117/12.725576 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This article introduces motion detection and estimation of low-level-light video sequence, and, motion detection, motion estimation and variational problem. Low-level-light video sequence different form others, the time and space domain noise in the signal not only limit the lowest illuminance of the system but also make the image show random glitter. In this paper how to improve the signal-to-noise ratio (SNR) of low light level image is discussed too. The results show that models and estimation algorithms in low-level-light video sequence can lead to improve reliability and accuracy of the estimated motion.

Select this Article		Research on a robot landmark localization system based on monocular camera Yuan Luo, Xiaodong Xu, and Yi Zhang Proc. SPIE 6279, 627952 (2007); http://dx.doi.org/10.1117/12.725579 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Robot localization is very important for the researching of intelligent robotics. The accurate of the robot coordinate will influence the control accuracy of the robot's moving action. So, it is essential for robot itself to have the ability to realize the modifying of coordinate of its own in real time when it is moving. In this paper, a robot landmark localization system based on a monocular camera is researched theoretical and experimental. Three longitudinal landmarks are used to assure the robust of the system. Digital image processing technology is enrolled to revise the image stretching and decrease the disturbing of noise. The experiments based on Pioneer III mobile robot show that this system can work well at different topographic situation without lose of signposts.

Select this Article		A new method of glare protection on highway real-time monitoring during nighttime Jin Xu, Zhebo Chen, Xuxiang Ni, and Zukang Lu Proc. SPIE 6279, 627953 (2007); http://dx.doi.org/10.1117/12.725583 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract When car run in highway during night, need switch on its headlight, for intensity of the light is very high, it will cause glare vision, the camera of monitoring system will be saturation, and all the other detail (For example: License plate) can't be shown on the screen except headlight and its glare. In this paper, introduce a new system and method of glare protection on highway nighttime monitoring, it can decrease the intensity of headlight and the glare vision in real-time, so the monitoring system could gain more details of highway from camera. The whole system's hardware is made up of outer camera-lens, inner camera-lens, spatial light modulator array and image sensor. The outer camera-lens images the objects (cars on highway) on the plane of the spatial light modulator array's panel. So, the spatial light modulator array can modulate part of the image on its panel, such as decrease or increase transmission ratio (or reflect ratio). The inner camera-lens images the spatial light modulator array's panel to the image sensor. So, the image on the image sensor is the image of object image after modulated. After the image sensor gained the image, we will use our software to analyze the image, use real-time processing to get the saturation and glared region. Firstly, we use threshold arithmetic to get the saturation and high intensive pixels of the image; secondly, we use filter to get ride of the noise made from threshold arithmetic, so we can get the region of saturation and glare region of the original image; thirdly, we do expand arithmetic at the direction of car's moving, and feedback the image to spatial light modulator. If we don't use expand arithmetic at the direction of car's moving, and feedback the image gained after step 2, for the car in highway is moving very fast, after the time of image processing, the car has moved to a new location with it's direction, so the feedback image will not decrease the light intensity of the car's headlight and it's glare region properly. For these three processes are decreasing the intensity of the image region, we called it negative feedback. At same time, we do positive feedback to increase the transmission ratio (or reflect ratio) at the low light intensity region, so that more details of the object will be imaging on image sensor. In fact, the image feedback on the spatial light modulator array is the composite of the negative feedback and positive feedback. In experiment, the spatial light modulator array is liquid crystal on silicon (LCoS), all image processing is on computer, the feedback image transfers via DVI bus. For the limit of operation system, the feedback time is about 100ms.

Select this Article		Automatic moving object segmentation in video sequence Xiaoyan Zhang, Yuguo Dong, and Xuchun Zhuang Proc. SPIE 6279, 627954 (2007); http://dx.doi.org/10.1117/12.725588 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel algorithm for automatic segmentation of moving objects from video sequences is proposed in this paper. Firstly, a fourth-orders statistic hypothesis testing in inter-frame difference is used to automatically separate the moving areas from the background in a general video sequence. Then the morphological filter is used to remove the noises and holes. Secondly, for three consecutive frames, superposition of the moving areas of first and second frame and that of second and third frame highlights the moving object areas of the second frame, the covered/uncovered background may be eliminated using such idea. Thirdly, the initial contour of the moving objects is determined by extracting the contour of the moving object areas and an improved active contour which uses the gradient vector as the external force guides the initial contour moving to the accurate moving object contour. Lastly, the motion compensation which uses the new three-step search algorithm is made to the moving object contour to obtain the initial contour of the next frame and the improved active contour is used again to correct the moving object contour of the next frame. Thus, following frames segmentation can be realized. Experiment testifies that the proposed algorithm is of few parameters, robust to noise and best in result of segmentation.

Select this Article		A novel mobile robot localization based on vision Yi Zhang and Yuan Luo Proc. SPIE 6279, 627955 (2007); http://dx.doi.org/10.1117/12.725591 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It is very important for mobile robot to correctly and fleetly locate. With the development of the theory and arithmetic of computer vision, vision navigation has become an important research direction in airmanship of mobile robot. In the paper, localization based on landmark is researched by using the camera of mobile robot on the basis of traditional localization method. A novel mobile robot localization based on vision is presented by using multi-sensor data fusion. It is showed from experiment data that the new localization method has better performance.

Select this Article		Design and implement of infrared small target real-time detection system based on pipeline technology Lihui Sun, Yongzhong Wang, and Yongqiang He Proc. SPIE 6279, 627956 (2007); http://dx.doi.org/10.1117/12.725592 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The detection for motive small target in infrared image sequence has become a hot topic nowadays. Background suppress algorithm based on minim gradient median filter and temporal recursion target detection algorithm are introduced. On the basis of contents previously mentioned, a four stages pipeline structure infrared small target detection process system, which aims at characters of algorithm complexity, large amounts of data to process, high frame frequency and exigent real-time character in this kind of application, is designed and implemented. The logical structure of the system was introduced and the function and signals flows are programmed. The system is composed of two FPGA chips and two DSP chips of TI. According to the function of each part, the system is divided into image preprocess stage, target detection stage, track relation stage and image output stage. The experiment of running algorithms on the system presented in this paper proved that the system could meet acquisition and process of 50Hz 240x320 digital image and the system could real time detect small target with a signal-noise ratio more than 3 reliably. The system achieves the characters of large amount of memory, high real-time processing, excellent extension and favorable interactive interface.

Select this Article		An approach of fast image mosaic based on binary region segmentation Xiaowei Han, Lei Yan, and Hongying Zhao Proc. SPIE 6279, 627957 (2007); http://dx.doi.org/10.1117/12.725423 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An approach of fast image mosaic is presented, which involves image matching and image intensity smoothing. Image matching includes two procedures, i.e. rough matching and fine matching. In rough matching, the overlapped regions of two adjacent images to be mosaicked are segmented to binary image at first. Then the binary images are filtered by open operation of mathematic morphologic method. In the binary image region of the reference image, feature template is searched and extracted on a given rule. Via XOR operation of the feature template and search region, some possible matching positions in the overlapped region of the other image are got. In the fine matching, the sequential similarity detection algorithm (SSDA) is adopted to perform matching computation in the small regions near the positions got in the rough matching, and then the relative position offsets in X-orientation and Y-orientation between the two adjacent images are got. Based on the result of the image matching, the two images are stitched. An approach of seam-line smoothing is adopted to adjust the intensity of the overlapped area. Simulation experimental results show that the approach greatly improves the operation speed, while the precision remains fine, so it can be applied in real-time mosaicking.

Select this Article		Real time recognition target under complicated background by using Vander Lugt correlator Wengang Hu, Jinyu Wang, Rui Xue, Xueju Shen, Wensheng Hua, and Yongzhong Wang Proc. SPIE 6279, 627958 (2007); http://dx.doi.org/10.1117/12.725425 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract An approach of in-situ measuring the complex response of a scene spatial light modulator which working in differential state was presented by using an image of Ronchi grating substituted for a concrete one. Its principle and testing method have been studied and a typical XGA2L11 spatial light modulator has been characterized. The scene image under complicated background has been edge enhanced by mapping the measurement results, and the correlation results showed that scene spatial modulator with the differential state can increase the SNR and PCE of correlation peak. The way could be wholly applied in Vander Lugt Correlator and has very strong practicability and effectiveness.

Select this Article		Rotation-canceling real time system of color video image Shengxiang Tao, Wei Ma, and Lizhi Qian Proc. SPIE 6279, 627959 (2007); http://dx.doi.org/10.1117/12.725371 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper puts forward an electronic rotation-canceling method based on high-speed DSP. The method adopts the rotation algorithm to counter rotate quantum components of luminance and chrominance for the image of each field, and then use the linear interpolation to resample and output pixels, thus realizing real time rotation-canceling of color video image.

Select this Article		State-space blur model for high-speed forward-moving imaging system and its recursive restoration Fengmei Cao, Xichun Chen, and Weiqi Jin Proc. SPIE 6279, 62795A (2007); http://dx.doi.org/10.1117/12.725376 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract When an imaging system is approaching the object at a high speed, because of the existence of integration time, the images obtained are always blurred radially. Since the degradation process is space variant, this kind of blur is difficult to handle, traditional frequency domain techniques can't be applied here. Obviously, the radially blurred image obtained is rotation symmetrical, so the usual uniformly sampled image can be resampled with fan-shaped grids, and the gray level of these new sampling points build up a new image matrix. The new image matrix's columns and rows are never the edges of the image, but the image's radius and angle. So, the original two-dimensional problem is simplified. Even after the resampling, the blur is still space variant, and the PSF (point spread function) will change along the radius direction. So the authors come up with a state-space method, a state-space blur model is constructed, which handles the problem recursively. To restore the degraded image simply means to find the inverse of the degradation system and computer simulation result shows the restoration algorithm restored the radially blurred image approvingly.

Select this Article		Detection of small moving targets in staring images sequence with complex background and low contrast Guo-hua Cao, You-shan Qu, Yan-fei Wang, Xue-wu Fan, and Cheng-zhi Su Proc. SPIE 6279, 62795B (2007); http://dx.doi.org/10.1117/12.725378 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A detection algorithm for small moving targets is proposed. The new algorithm firstly utilizes convolution filtering for noise smoothing, and then a proposed preprocessing method based on the norm of the difference vectors of the processed images sequence is applied to remove most of low-frequency background. Furthermore, optic flow technique is adopted to segment the doubtful small moving targets from the subimage remained by preprocessing. Finally, the statistic information for each of doubtful small moving targets is calculated. From the statistical feature, a determining criterion is established to determine whether each of the doubtful small moving targets is a true target or not. Because the preprocessing approach can get rid of most of the low-frequency background effectively, the calculation quantity of the sequential processing by optic flow is decreased largely. The experiments in a designed test system prove that the proposed detection algorithm can detect small moving targets in 30fps, 512x512 pixels, staring images sequence with SNR no less than 3dB, and the correct detecting probability is up to 96%, which can satisfy the real time processing requirements in practice.

back to top

Poster Session: Diagnosis of Ultrafast Phenomena

Select this Article		High-speed diagnostic pulsewise-periodic of electric discharge in water Victor A. Kolikov, Mikhail E. Pinchuk, Anatoly G. Leks, and Philipp G. Rutberg Proc. SPIE 6279, 62795C (2007); http://dx.doi.org/10.1117/12.725381 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The results of research of pulsewise-periodic discharge in a water with a periodic time from 10 Hz up to several kHz, duration of discharge impulse 1-50 s, current amplitude 10-100 A, current rise rate from 10⁶ A/s to 10⁸ A/s are presented. The optical diagnostic of electric discharge in a water is carried out by the high-speed miniature 9-frame image converter camera K-011, one frame camera NanoGate-1 and the spectrograph with ICCD. The camera K-011 allows to register up to 9 frames with an exposition up to 0.1 s and time between frames up to 0.1 s. The exposure time of NanoGate-1 is up to 10 ns. The registration of spectra can be carried out with an exposition up to 5 ns. The program complex allows to record of a series of discharge impulses. The main discharge parameters was determined by this high-speed optical diagnostics: discharge channel temperature, velocity of channel expansion, compression waves dynamic was determined. The feature of the channel formation were detected in unipolar mode of discharge and in oscillate mode.

Select this Article		High-speed optical studies of the long sparks in very transient stages Yuri V. Shcherbakov, Vitaly B. Lebedev, Vladimir A. Rakov, Grigori G. Feldman, Boris N. Gorin, Vladimir S. Syssoev, and Maksim A. Karpov Proc. SPIE 6279, 62795D (2007); http://dx.doi.org/10.1117/12.725386 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High-speed optical studies of different stages of the long sparks have been carried out at the High Voltage Research Center (HVRC), Istra, Russia, using up to three devices operated synchronously: two novel universal streak and framing cameras K004M and K008 developed by the BIFO Company and an analog image converter streak camera of FER14- type instrumented with a CCD readout system of SU04-type. Special attention was paid to the improved spatiotemporal resolution when recording the pictures of large sizes. The measurements were conducted in rod-to-plane gap of 5.5÷6 m in length under both polarities HV pulses of 2÷3 MV in altitude with waveform of 20/7500 and 100/7500 s. Under negative polarity, an additional thin metallic rod about of 1 m in length was placed on the grounded plane to provide an origin of the positive upward leader and its reliable observation. The velocity of approaching the downward negative streamer-leader system and upward positive leader toward each other near the junction point has been found to be around 5÷10 m/s. Some supporting exemplary pictures have been recorded to additionally clarify the phenomenology of the stepped or/and attempted leaders, which can be useful for analysis of long spark and lightning treeing and development.

Select this Article		High-speed velocity measurements on an EFI-system W. C. Prinse, P. G. van't Hof, L. K. Cheng, and J. H. G. Scholtes Proc. SPIE 6279, 62795E (2007); http://dx.doi.org/10.1117/12.725402 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For the development of an Exploding Foil Initiator for Insensitive Munitions applications the following topics are of interest: the electrical circuit, the exploding foil, the velocity of the flyer, the driver explosive, the secondary flyer and the acceptor explosive. Several parameters of the EFI have influences on the velocity of the flyer. To investigate these parameters a Fabry-Perot Velocity Interferometer System (F-PVIS) has been used. The light to and from the flyer is transported by a multimode fibre terminated with a GRIN-lens. By this method the velocity of very tiny objects (0.1 mm), can be measured. The velocity of flyer can be recorded with nanosecond resolution, depending on the Fabry-Perot etalon and the streak camera. With this equipment the influence of the dimensions of the exploding foil and the flyer on the velocity and the acceleration of the flyer are investigated. Also the integrity of the flyer during flight can be analyzed. To characterize the explosive material, to be used as driver explosive in EFI's, the initiation behaviour of the explosive has been investigated by taking pictures of the explosion with a high speed framing and streak camera. From these pictures the initiation distance and the detonation behaviour of the explosive has been analyzed. Normally, the driver explosive initiates the acceptor explosive (booster) by direct contact. This booster explosive is embedded in the main charge of the munitions. The combination of initiator, booster explosive and main charge explosive is called the detonation train. In this research the possibility of initiation of the booster by an intermediate flyer is investigated. This secondary flyer can be made of different materials, like aluminium, steel and polyester with different sizes. With the aid of the F-PVIS the acceleration of the secondary flyer is investigated. This reveals the influence of the thickness and density of the flyer on the acceleration and final velocity. Under certain circumstances the flyer breaks up in several parts and several velocities at the same time have been recorded. Several flyer materials and dimensions exist that are able to initiate very insensitive explosives like TATB.

Select this Article		Femtosecond study of electron transfer dynamics of anionic-cationic cyanine dye J-aggregates to AgBrI microcrystals Guangsheng Fu, Shanshan Fan, Chunlei Li, Guozhi Fan, Xiaowei Li, and Shaopeng Yang Proc. SPIE 6279, 62795F (2007); http://dx.doi.org/10.1117/12.725443 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Using femtosecond time-resolved upconversion fluorescence spectroscopy technology, the fluorescence decay properti-es of J-aggregates of anionic-cationic cyanine dye, anionic cyanine dye and cationic cyanine dye adsorbed on surfaces of the cubic AgBrI grains are investigated. The kinetics of the electron transfer and the spectral sensitization property are analyzed in detail. The experiment setup in our work is the fluorescence upconversion(also called fluorescence frequen-cy generation)spectrometer. The time-resolution reaches about 140 fs. Anionic-cationic cyanine dye studied in our ex-periment is new-type cyanine dye, which formed by anionic cyanine dye reacting with cationic cyanine dye. By contrary of the sensitization performances of several cyanine dyes, It is found that the sensitization performance of cubic AgBrI sensitized by anionic-cationic dye is marked higher than those of anionic cyanine dye, cationic cyanine dye and the mixture of anionic cyanine dye and cationic cyanine dye. The fluorescence decay curves of cyanine dyes J-aggregates obtained by femtosecond fluorescence upconversion spectrometer are analyzed as a sum of double exponent-ials, and the fitting curves consist of a fast and a slow component. Because of the large amplitude, this fast decay should be mainly attributable to the electron transfer from dye J-aggregates to conduction band of AgBrI. The electron transfer velocity of anionic-cationic cyanine dye J-aggregates is larger than those of anionic cyanine dye, cationic cyanine dye and the mixture of anionic cyanine dye and cationic cyanine dye, which is consistent with the results of the sensitization performance and the photoelectron lifetime. Dye1 has higher sensitizing efficiency than other cyanine dyes on the cubic AgBrI grains.

Select this Article		Extracting protein folding kinetics in single-pair fluorescence resonance energy transfer experiment based on wavelet analysis Guangcun Shan and Wei Huang Proc. SPIE 6279, 62795G (2007); http://dx.doi.org/10.1117/12.725429 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Dynamic structural changes of protein folding and biological macromolecules undergoing biochemical reactions can be monitored and studied using the single-pair fluorescence resonance energy transfer (sp-FRET) spectroscopy tool. In this work, we have simulated a single-pair FRET photoemission process as an illustrative model example, where a FRET pair resides on a folding protein that undergoes diffusion in water. And then we apply the wavelet analysis method, which is a widely used method in many fields, such as the digital signal processing, noise reduction and the data compression (JPEG2000), to deal with the case of fluorescence resonance energy transfer (FRET) experiment for protein folding. It is shown that the wavelet analysis filter facilitates the detection of various intermediate conformational states in a noisy trajectory. Thus it is finally suggested that it is particularly suitable for sp-FRET spectroscopy studies of protein folding and can be of use for directly extracting the folding energy landscape. Our study establishes potentially useful data analysis technique and theoretical guidelines for the study of sp-FRET spectroscopy experiments.

Select this Article		Inversing chlorophyll-a concentration by multi-temporal models using TM images Yunmei Li, Wanning Lu, and Haijun Wang Proc. SPIE 6279, 62795H (2007); http://dx.doi.org/10.1117/12.725430 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Chlorophyll is a very important parameter for lake water quality evaluation. Its concentration varies seriously with different season. The chlorophyll-a concentration inversing models in different season were studied using different temporal TM images. The models were built in 3 steps: Firstly, 10 images were selected according to the principle of almost synchronously with in situ measurement; secondly, remote sensing images were preprocessed. Atmospheric corrections were carried out use 6S model, and then, the images were geometric corrected; lastly, the optimum models for chlorophyll-a concentration inversing were discussed for multi-temporal TM images. The water quality parameters were measured on 21 sample points in Tai Lake, China monthly as the monitoring network. The chlorophyll-a concentration inversing models were built using semi-empirical approach by the integrated use of multi-temporal remote sensing data and in situ data. The spectrum character of chlorophyll was analyzed following other's studying. Then the different composed bands and component modes such as TM4/TM3, (TM4-TM3)/(TM4+TM3), TM3*TM4/ln(TM1), etc. were discussed for building the regression models. The inversing accuracy was evaluated by relatively error. The optimum models were selected for each month by comparing the different models. It could be concluded that: The mode of multi-temporal equations might be the same or similar for different month. But the coefficients were quite different; the reflectance of TM3 and TM2 band were the most often used parameter for model building; the estimated accuracy increased with raising chlorophyll-a concentration. For example, when the chlorophyll-a concentration was lower than 0.009mg/l, the estimated value was not so accuracy. But when the chlorophyll-a concentration raised to 0.05mg/l the relatively errors for all samples were less than 30%.

back to top

Poster Session: Sensors for High-Speed Diagnosis (CCD, CMOS, Etc.)

Select this Article		A new high-speed image sensing technique based on an ordinary CCD Guotian He, Xiangzhao Wang, Dailin Li, and Jianmin Hu Proc. SPIE 6279, 62795I (2007); http://dx.doi.org/10.1117/12.725432 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, the reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing technique with adjustable frame rate based on an ordinary CCD was proposed. The principle of the image sensor was analyzed. When the maximum frequency and channel bandwidth were fixed, a custom high speed camera was designed by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been enhanced by reducing the number of pixels of every frame, therefore the ordinary of CCD can be used as the high frame rate image sensor with small pixels. The multi-output high speed image sensor with small pixels by using this technique can overcome the deficiencies of low resolution, low accuracy, and high price. The light intensity varying with time was measured by using the image sensor. The frame rate was less than 1600frame/second, and the size of every frame and the frame rate was adjustable. The correlation coefficient between the measurement result and the normal value was higher than 0.95, and the relative error was lower than 0.52%. The feasibility of the high-speed image sensing technique was proved by the experiments.

Select this Article		Research on CCD video signal processing based on correlated double sampling X. Q. Wu, L. Zhang, X. J. Li, and X. W. Xu Proc. SPIE 6279, 62795J (2007); http://dx.doi.org/10.1117/12.725434 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In CCD detection to micro signals, it is a key technique that the output noise signals of CCD must be restrained or attenuated, so that SNR (Signal-to-Noise Ratio) can be enhanced. This paper initially presents a brief description on the characteristics of CCD output signals and usual processing schemes. And then, CCD output noise characteristics being concerned, CDS (Correlated Double Sampling) is carefully analyzed. Lastly, on the basis of establishing CDS transfer function and noise analysis model, the most proper CDS scheme is employed to test the performance of restraining KTC noise and other low-frequency noises existed in CCD signals. And the results show that if only proper sample time is chosen, 2 -CDS circuit can not only remove KTC noise, but also restrain low-frequency noises and other white noises in different degrees.

Select this Article		On the relationship between the illumination of bubble in water and the CCD gray pattern Hui Ning and Yuanhe Tang Proc. SPIE 6279, 62795K (2007); http://dx.doi.org/10.1117/12.725436 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Getting clear photographs of bubbles in water and extracting bubbles in the image of aerated water flows are the basis to analyze the characteristics of water flows by image measurement. Because the bubbles in water are colorless, transparent and deforming continuously, furthermore, they reflect and refract light at their boundaries. Up to now, almost all the image processing of bubbles extraction in the images of aerated water flows have problems of miss-extraction or deformity of bubbles which caused by un-uniformity of bubbles' boundary resulted from the un-balance illumination of the image. In order to eliminate the noises in the background and identify the blurry boundaries, based on the systematic analysis of the optical properties of bubbles in water, a set of formulas calculating the relationship between image gray and bubble luminance are deduced in this paper which are applicable to different illumination settings and different CCD. A new method is developed to forecast CCD gray pattern based upon illumination variable and bubble shape, which was demonstrated by the experiments. The proposed method is expected to be used to design experimental scheme of image measurement, and can help to enhance the accuracy of image analysis.

Select this Article		Ultra-short electromagnetic pulse used for target detection Chi Ruan, Wei Zhao, Guo-Fu Chen, Bai-Yu Liu, and Shao-Lan Zhu Proc. SPIE 6279, 62795L (2007); http://dx.doi.org/10.1117/12.725439 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Two common approaches to generate ultra-short electromagnetic pulse are presented in this paper. One is that using a high-speed avalanche transistor and another is that using a laser triggering photoconductive semiconductor switch (PCSS). An ultra-short electromagnetic pulse with the rise time of 190 picosecond (ps), the pulse duration of 290 ps and the amplitude of 2.2 kV, is radiated by an ultra-wide band (UWB) antenna. It is noted that the ultra-wide frequency spectrum provided by the ultra-short electromagnetic pulses with duration of picosecond can be used to distinguish different targets. The radiated pulse would transmit and be reflected by various targets within the detection range. By analyzing the reflected signal, the corresponding reflection material can be discerned. The experiment is set up to distinguish the iron metal and concrete wall respectively. The results show that such ultra-short pulse technology has an excellent ability to distinguish objects.

Select this Article		The research on binocular vision based real-time object indication recognition method Chuncan Li, Zhijiang Zhang, and Zhihua Dong Proc. SPIE 6279, 62795M (2007); http://dx.doi.org/10.1117/12.725440 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In order to achieve a non-contact interactive operation in particular conditions such as high-temperature, high-voltage conditions and space capsules, a real-time indicated object recognition method is proposed in this paper. It combines eye-finger moving information to estimate the object position. Multi-camera is used to get images containing fingertips and eyes, and binocular vision principle is utilized to estimate the 3D position of fingertips and eyes. According to physiological characteristic, when people indicate objects, the line linking the center of his two eyes and fingertip will pass the object point. So after capturing eyes and fingertips in video stream images with feature point extracting algorithm, a model from 2D image coordination to object scene coordination which can be expressed as a projective translation with multi-view restriction is presented. Using this model, 3D position of eyes and fingertips can be estimated from 2D positions in images, and the line linking the center of a person's two eyes and his fingertip is obtained. Intersecting this line and the plane which the object stand on it produces the object point which is the point indicated by the person's finger. This method estimates the absolute position of the object, which means it needn't users to provide any initial benchmark information. Finally, this method is tested by a practical indicated object recognition system with error analysis of camera calibration and image processing result.

Select this Article		Simultaneous phase-shifting interferometry based on high-speed CCD Fen Zuo, Lei Chen, and Chunsheng Xu Proc. SPIE 6279, 62795N (2007); http://dx.doi.org/10.1117/12.725441 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new simultaneous phase-shifting measuring method based on Twyman-Green polarization phase- shifting technique is presented. In the corresponding set-up, a 2-dimentional grating is applied. By the grating, 4 diffracted beams of (±1, ±1) orders are formed for the same diffracting efficiency. Each is let to pass one of four polarizing plates respectively, polarization directions of which differ in turn by 45°. So four interferograms with 90°phase-shifting interval are frozen simultaneously by a high-speed CCD, which has short exposure of 1/10000 s. Moreover, by the use of 4-bucket algorithm, a profile of the test surface is thus derived. Meantime, the system is deposited on a vibration-isolate flat, and the structure of an ordinary piezoelectric transducer (PZT), with a time response above 1000 Hz at amplitude of λ/2, is used to simulate an epicenter, the frequency of which varying from 10 Hz to 200 Hz. In addition, the experimental results reveal that the advanced system has a high testing precision and testing repeatability in the vibrational environment whose amplitude- frequency product is less than 100 Wave-Hertz. Therefore, the proposed system has enough endurance to the vibration during on-line optical testing.

Select this Article		Development of high frame rate CCD image remote acquisition system Haibing Zhang, Binkang Li, Linbo Ruan, Bing Feng, and Mingan Guo Proc. SPIE 6279, 62795O (2007); http://dx.doi.org/10.1117/12.725445 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a high frame rate Charge Coupled Device (CCD) image acquisition system. The emphasis is the data transmission and the data recording technology. The DALSA CCD camera head CA-D6 is utilized as the system imaging unit. The CA-D6 output 35 pairs and input 2 pairs Low Voltage Differential Signals (LVDS) are analyzed. The switch from LVDS to TTL signals is implemented. A pair of Agilent data transceivers HDMP-1022/HDMP-1024 is used to encode/decode the digital image data. The system timing block is designed on Complicated Programmable Logic Device (CPLD) technology. The internal program is explored on VHDL and schematic combination technology. The optic-fiber transceiver HFCT-53D5 is applied to complete the data transmission to remote area. The VC++ environment application software is developed based on data the acquisition card PCI-7300A. The imaging system can work at the frame rate of up to 955fps. The transmission data rate can reach 1Gbps, and it can transmit the image data beyond 1.5 km area. The system can be used in remote high-speed image acquisition field such as explosion analysis and radiation diagnosis.

Select this Article		Design and study of an new crepuscular imaging CCD Yufei Du, Yuanhe Tang, Kai Liu, Hui Ning, Lei Zhang, and Haowei Li Proc. SPIE 6279, 62795P (2007); http://dx.doi.org/10.1117/12.725448 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novelty circumambulating transferred area array CCD (Charge Coupled Device) working method is proposed, and its work feasibility is proved. The new CCD can change the existing CCD complex structure, enhance the translational velocity and transfer efficiency, reduce the design production cost and the dark current through the best electronic transfer frequency. To solve the limitations of big noise which contemporary exists on glimmer imaging plan in IICCD (Image Intensified Charge Coupled Devices) and EBCCD(Electron Bombarded Charge Coupled Devices), short life and other shortage, the weak optical image detect-ability is enhanced through changed the CCD periphery ancillary facilities and micro-channel electron vase plate is designed. It is proved through changing dispersivity of the photocathode electron emission once time and divergence of the speed, improved secondary electron launch randomness of imagining intensifier, then reduced the system the dynamic survey noise, enhanced IICCD and the EBCCD survey limitation.

Select this Article		Synchronous control analysis of TDI-CCD imaging system L. Zhang, Y.X. Li, and X. W. Xu Proc. SPIE 6279, 62795Q (2007); http://dx.doi.org/10.1117/12.725451 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper describes structure and principle of TDI-CCD image sensor. With help of the Modulated Transfer Function (MTF), the negative effect on image quality is fully analyzed, which is caused by the mismatch between TDI-CCD line scanning and velocity of image motion. After theory analysis and experiments, the results show that within the Nyquist frequency, only the synchronous error is strictly controlled in the range of ±2%, and a continuous four-phase imaging clock is employed, the effects of image motion is basically eliminated during process of imaging.

Select this Article		Review of current developments and trends of CMOS image sensors Huimin Chen, Ping Li, Xuebing Zheng, Jianqiang Sun, and Kun Li Proc. SPIE 6279, 62795R (2007); http://dx.doi.org/10.1117/12.725454 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract With the development of VLSI, CMOS image sensor has developed increasingly. The history of CMOS image sensor was introduced, on the basis of analyzing the principle of CCD and CMOS image sensor, the advantages of CMOS image sensor was summarized. The current research status and commercial productions of different companies were described in this paper, moreover, the technical specifications were presented. At last, the current applications and trends of CMOS image sensor was focused.

Select this Article		Study CCD image motion for remote sensing detection Peng Lv, Yuanhe Tang, Kai Liu, Binglong Zhang, Shijia Wang, and Yufei Du Proc. SPIE 6279, 62795S (2007); http://dx.doi.org/10.1117/12.725458 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For remote sensing to measure upper atmospheric wind field by optical passive method on-load satellite, the emission source is used of crepuscular aurora of OH 732.0nm. The time of exposure is need about 9sec by remodel Sagnac interferometer, so there is a larger image motion on CCD and the measurement precision is limited. This paper has been calculated the CCD image motion quantity based on remodel pushbroom model by Sagnac interferometer. The MTF curve is demonstrated the image motion can be compensated. Then the techniques of TDICCD, the whole frame transfer, swing mirror and photon memorizer to use compensate the image motion quantity.

back to top

Poster Session: Shock Wave and Hypersonic Physics

Select this Article		Planar nanosecond shock wave generation and propagation in poly vinyl alcohol investigated by CARS Li Huang, Yanqiang Yang, Yinghui Wang, Pengcheng Jin, Zhiren Zheng, Wenhui Su, and Dana D. Dlott Proc. SPIE 6279, 62795T (2007); http://dx.doi.org/10.1117/12.725462 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Planar nanosecond shock waves were generated with ultrafast Gaussian laser pulses by using saturable dye-doped polymer film as shock layer. Ultrafast spatially resolved Coherent Anti-Stokes Raman (CARS) spectra of shock compression of a polycrystalline anthracene optical gauge were measured, and temporal profile and velocity of the shock pulse were obtained. Detailed measurements showed the shock pressure, as indicated by the blueshift of an anthracene vibrational transition, and the shock velocity, as indicated by the arrival time of shock wave at the anthracene gauge layer, remains constant within better than 5% over the central region probed by CARS.

back to top

Poster Session: Photonics

Select this Article		Novel high-resolved spectroscopic studies of positive streamer corona Yuri V. Shcherbakov Proc. SPIE 6279, 62795U (2007); http://dx.doi.org/10.1117/12.725483 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We have developed a fully self-consistent method of diagnostics of streamer discharge plasmas based on analysis of absolute intensities of the second positive (SPS) and first negative (FNS) systems of molecular nitrogen. The theory of the method combines a spectroscopic technique for calculation of temporal waveforms of the nitrogen absolute SPS and FNS (0,0)-band emission and a self-consistent semi-analytical parametric axially symmetric 1.5D model of the filamentary streamer head. The spectroscopic technique takes into account characterizations of all units of the measuring spectro-optical channel, including spatiotemporal resolution and resolution in wavelength. The model of the streamer head is characterized by some trial consistent allowable parametric on-axis profile of the electric field combined with the electron and total space charge number density profiles fully self-consistent each with other and with the trial electric field; all those expanded to 2D configuration via ellipse-like geodesic lines. The absolute values and the synchronous ratio of the 1L spatially and time-resolved cross-correlated temporal waveforms of the SPS to FNS (0,0)-bands have been used to reconstruct 2D structure of the streamer head. With a procedure fitting the directly computed output voltage waveforms to the experimental ones, the peak values of the electric field and of the electron number density within streamer head at mid-gap distances have been found to be 430÷500 Td and (2÷3)×10¹⁴ cm^-3, respectively. The corresponding absolute electric field became thus 70÷80 kV/cm at initial gas temperature within the repetitive streamer region of 450 K. The results corroborate principal conclusions of the current-day streamer theory and numerical modeling.

Select this Article		Property of a reflected Gaussian pulse beam Jiyue Zhang, Guoku Ge, Duan Tao, and Chunfang Li Proc. SPIE 6279, 62795V (2007); http://dx.doi.org/10.1117/12.725446 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract It is theoretically discussed the reflective property of a Gaussian pulse on the planar dielectric interface. When the decoupling and full-interference approximations are considered, the axes of reflected pulse beam undergoes a lateral shift from the position predicted by geometrical optics. At the same time, the reflected pulse beam still emerge the time delay comparing to the incident pulse beam. The reflected profile is different from the incident pulse beam. Both spatial distribution and temporal distribution of the reflected pulse beam come out the aberrance.

Select this Article		Comparison of Fourier-transform analysis with wavelet-transform analysis in terahertz time-domain spectroscopy Liying Lang, Xueguang Wang, Yuqiang Deng, Qirong Xing, Lu Chai, and Qingyue Wang Proc. SPIE 6279, 62795W (2007); http://dx.doi.org/10.1117/12.725463 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, we applied wavelet-transform to analysis the water vapor absorption spectroscopy in terahertz range, and compared with conventional Fourier-transform analysis in terahertz time-domain spectroscopy. The extracted absorption lines are in excellent agreement with the results of using Fourier-transform analysis. The results show that wavelet-transform analysis of the absorption spectrum delivers accurate absorption lines in THz range. Because the results are shown in a time-frequency domain, it gives a more intuitive image on when the absorption happens at which frequency. Combining wavelet-transform technique with THz-TDS, we hope there births a new spectroscopy: the wavelet-transform terahertz time-domain spectroscopy.

Select this Article		Design of hybrid diffractive/refractive optical system by the method of P-W-C Xinhua Hong, Liwu Chen, Jianfeng Yang, and Baochang Zhao Proc. SPIE 6279, 62795X (2007); http://dx.doi.org/10.1117/12.725482 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The structure parameter of hybrid diffractive/refractive optical system has been solved by the method of P-W-C. The primary aberration equation for diffractive system has been deduced. Combination of 3 pieces lenses, the diffractive/ refractive hybrid optical system was designed: No.1 and No.3 are common glasses; No.2 is binary optical lenses (BOL). The results show: The Longitudinal Aberration is good in 0.6 and 0.8~0.9 apertures for the lenses. When frequency is 30lp/mm, the modulation transfer function (MTF) is close to diffractive limit in 0.5 field angle; the modulation transfer function (MTF) is close to 0.7 in edge field. The design method can be used for diffractive/ refractive hybrid optical system.

Select this Article		Research and fabrication of integrated bio-sensor for blood analysis based on μTAS De En, Jianxia Wei, Zhengrong Tong, Caihe Chen, Yuming Cui, Kexin Xu, Qin Si, Chao Li, and Jie Liu Proc. SPIE 6279, 62795Y (2007); http://dx.doi.org/10.1117/12.725485 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For simultaneously detecting multi-parameters of blood in the clinical diagnosis, the analysis apparatus should be smaller in size, more reliable and sensitive. So a kind of integrated bio-sensor for blood analysis based on Micro Total Analysis System (μTAS) is presented. It provides modern bio-sensor prospect with a novel technology. A multi-parameters of blood analysis integration sensor is μTAS bio-sensor based on 4 groups of interdigital array (IDA)microelectrodes. The IDA microelectrodes are fabricated on glass substrates by photography, film deposition and other microfabrication techniques. Thin-film gold microelectrode with a thickness of 250nm is deposited on a chromium-adhesion layer. The finger microelectrode width and space are both 10μm. The work space is 2×2cm². The concentration of Blood sugar, Total Cholesterol, Acetone body and Lactic acid is measured by detecting steady-state limiting currents in IDA microelectrodes modified with enzymes on the "generate-collect" mode. Blood distribution structure is designed and fabricated, to distribute blood and isolate reaction areas. By contrasting two kinds of process flow based on lift-off and etching, etching is adopted to preparation method of microelectrode. A multi-channel apparatus for current measurement is accompleted. The system characteristics of the bio-sensor are tested. The curve of the apparatus time to current response is achieved by testing on real-time. The relationships between parameter concentration and current are analyzed in detail. The experimental data indicates: current measurement dimension 0~40μA, certainty of measurement 0.1μA, the performances of the bio-sensor meets design requirement.

Select this Article		Beam-smoothing investigation on Heaven I Yi-huai Xiang, Zhi-xing Gao, Xiao-hui Tong, Hui Dai, Xiu-zhang Tang, and Yu-sheng Shan Proc. SPIE 6279, 62795Z (2007); http://dx.doi.org/10.1117/12.725487 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Directly driven targets for inertial confinement fusion (ICF) require laser beams with extremely smooth irradiance profiles to prevent hydrodynamic instabilities that destroy the spherical symmetry of the target during implosion. Such instabilities can break up and mix together the target's wall and fuel material, preventing it from reaching the density and temperature required for fusion ignition.^1,2 Measurements in the equation of state (EOS) experiments require laser beams with flat-roofed profiles to generate uniform shockwave³. Some method for beam smooth, is thus needed. A technique called echelon-free induced spatial incoherence (EFISI) is proposed for producing smooth target beam profiles with large KrF lasers. The idea is basically an image projection technique that projects the desired time-averaged spatial profile onto the target via the laser system, using partially coherent broadband lighe. Utilize the technique, we developing beam- smoothing investigation on "Heaven I". At China Institute of Atomic Energy , a new angular multiplexing providing with beam-smoothing function has been developed, the total energy is 158J, the stability of energy is 4%, the pulse duration is 25ns, the effective diameter of focusing spot is 400um, and the ununiformity is about 1.6%, the power density on the target is about 3.7×10¹²W/cm². At present, the system have provided steady and smooth laser irradiation for EOS experiments.

Select this Article		Research on light signals extraordinary compressed using periodic structure modulated method in photorefractive materials Mengchao Li, Yanmin Li, Gang Zheng, and Songlin Zhuang Proc. SPIE 6279, 627960 (2007); http://dx.doi.org/10.1117/12.725503 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract During some high processing, such as high-speed photography and so on, the encode pulse or driving signal must be compressed with full optics system. According to the light speed can be slowed down in a photorefractive crystal bar in which written volume-index grating by two laser beam, so as to the light signal may be transmitted in slow speed under 1/ 7 of light speed in vacuum. Because the genesis of the phenomenon is the inner index periodic structure, so the out put signal compressed may be realized through erasing the periodic structure in the opposite direction of signal beam using another laser beam when the signal light transmitting the crystal bar. However, every finite signal stream can be further compressed by the same way again. Different erasing method would get many kinds of out put signal to adapt to various design.

Select this Article		Measurements of fibers' thermal-optic coefficient based on optical fiber Bragg grating sensor Jing Ye, Baojin Peng, Jianwen Fang, Tiefei Huang, Yan-biao Liao, and Min Zhang Proc. SPIE 6279, 627961 (2007); http://dx.doi.org/10.1117/12.725504 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Optic fibers are applied in the field of high speed photography more and more, for its good properties. At present, various new-style fibers come out, and these new-style optic fibers' core material are not based on pure quartz traditionally. To know the new-style fibers' properties quantitatively, thermal-optic coefficient is indispensable to get. Therefore this article describes a new way to measure fibers' thermal-optic coefficient based on optical fiber Bragg grating(FBG) sensor. With a temperature referrence grating and a measuremental grating, experimental system is developed, combined with the characteristics of fiber Bragg grating. Experimental setup and measurement principle are discussed. The result of experiment proves that the system can solve the existent cross sensitive problem which caused by temperature and the strain effectively. The fibers' thermal-optic coefficient are measured successfully, within ±1%.

Select this Article		Analysis on strain and temperature sensing characteristic of sampled fiber grating Dandan Zhu, Zhiquan Li, Xiuxian Tian, Fu Sun, and Haifang Wang Proc. SPIE 6279, 627962 (2007); http://dx.doi.org/10.1117/12.725505 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Sampled fiber Bragg grating(SFBG) has caused extensive research interest due to its special filtering characteristic, strict wavelength interval, compact structure, easy integration and low cost etc. Based on coupling-mode theory, the reflective spectrum of sampled fiber Bragg grating was analyzed using transmission matrix method. Strain and temperature sensing characteristics of sampled fiber Bragg grating were discussed in the paper. Wavelength shift and transmission intensity vary linearly with strain and temperature. The change of strain and temperature can be determined simultaneously by a single sampled fiber grating. In the experiment, the strain and temperature of sampled fiber Bragg grating change simultaneously, the photoelastic coefficients of sampled fiber Bragg grating were P₁₁=0.121, P₁₂=0.27. The Poisson ratio of optical fiber core stuff was 0.17, the thermal expansion coefficient was 5.5×10^-7/°C, and the calorescence coefficient of optical fiber was 8.3×10^-6/°C. We can get that A, B, C and D were separately -0.00055nm/, 0.013nm/°C, - 0.00033/, -0.00011/°C by calculating. Strain measurement ranged from 0 to 2500. Temperature measurement ranged from 0°C to 300°C.

Select this Article		Continuous-wave diode-pumped Yb³⁺:LYSO tunable laser Juan Du, Xiaoyan Liang, Yi Xu, Ruxin Li, Chengfeng Yan, Guangjun Zhao, Liangbi Su, Jun Xu, and Zhizhan Xu Proc. SPIE 6279, 627963 (2007); http://dx.doi.org/10.1117/12.725506 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A new alloyed crystal, Yb:LYSO, has been grown by the Czochralski method in our institute for the first time, and its effective diode-pumped cw tunable laser action was demonstrated. The alloyed crystal retains excellent laser properties of LSO with reduced growth cost, as well as the favorable growth properties of YSO. With a 5-at.% Yb:LYSO sample, we achieved 2.84 W output power at 1085 nm and a slope efficiency of 63.5%. And its laser wavelength could be tuned over a range broader than 80nm, from 1030nm to 1111 nm. This is the broadest tunable range achieved for Yb:LYSO laser, as far as we know.

Select this Article		Fiber micro-vibration readout sensor based on MOEMS Rui Li, Wen Xiao, Dewen Liu, and Yu Cui Proc. SPIE 6279, 627964 (2007); http://dx.doi.org/10.1117/12.725507 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract To measure the vibration of micro-structure, a scheme of sensor based on MOEMS (Micro-Optic-Electro-Mechanical System) with fiber-optic readout was proposed, and its mathematical model was deduced. Single-fiber readout structure and a micro-structure fixed in the front of the sensor were used. The micro-structure vibrated as the measured object moved, and its vibration caused the change of light intensity. The sensor detected vibration displacement by receiving the light intensity. As a result of single-fiber structure and parameters optimization of micro-structure, compared with other fiber readout structures, this system has the advantages of high sensitivity and miniaturization which is easier to match with fiber system because of single-fiber structure and parameters optimization of micro-structure. The response behaviors of the system to the piezoelectric ceramics excitation were studied through the experiments. And it could detect the vibration displacement of 0.18nm.

Select this Article		Research on the active recovery technology of optical fiber radiation effect Yanling Han, Wen Xiao, Xiaosu Yi, and Yunchun Zhang Proc. SPIE 6279, 627965 (2007); http://dx.doi.org/10.1117/12.725597 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The light transmission characterizes of the optical fiber was changed when it has been exposed in the radiation environment due to the radiation induced defects and the formation of color centers. On the other hand, the damage of crystal lattice was recombined simultaneously due to the effect of light or thermal when the color centers were forming. Moreover the effect assisted by light is commonly called photobleaching which is directly proportional to the light power and inversely proportional to the light wavelength. Based on the effect, the radiation induced loss can be reduced by emitting high-power light to fiber. In this paper, the active recovery effect has been put forward to reinforce the fibers' radiation resistance using two sources after the detailed analysis of the fiber radiant effect and color center model. In addition, the application importance of the methods was also discussed.

Select this Article		Research on dual phase-shifted fiber gratings sense and signal disposal Ke-Jia Wang, Qi Wang, and Yi Wang Proc. SPIE 6279, 627966 (2007); http://dx.doi.org/10.1117/12.725722 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper proposes a kind of scheme that uses dual way to construct a differential type fiber gratings sensor and signal control method. The sensor utilizes cantilever structure to little answer sense and possesses better optical frequency heterodyne regulated performance via stepper motor modulation. The dual differential type phase-shifted fiber gratings can be convenient regulation and scans frequency to proceed to heterodyne laser communication. It is proved that the scheme possesses many excellent characteristics such as upper sensitivity, powerful anti-jamming capacity. The scheme enters into a new domain of laser atmospheric communication system signal demodulation.

Select this Article		The coherence properties of supercontinuum spectra generated in photonic crystal fiber Yuan Guo, Shuangchen Ruan, Yongqin Yu, and Yuncai Wang Proc. SPIE 6279, 627967 (2007); http://dx.doi.org/10.1117/12.725724 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Temporal coherence property of supercontinuum (SC) generated in a polarization-maintaining photonic crystal fiber (PM-PCF) pumped by Ti:sapphire fs laser was experimentally studied by using a modified Michelson interferometer. The coherence length of supercontinuum light was measured to characterize the temporal coherence property. The coherence lengths of supercontinuum and pump laser were measured to be 6.5 m and 59.14 m, respectively. The shortened coherence length of supercontinuum output from the PM-PCF was due to the broadened spectrum. Moreover, the interferogram evolution versus the supercontinuum spectra was also investigated. It was indicated that the flatter the supercontinuum was, the better the interferogram was.

Select this Article		Simultaneous strain and temperature measurement system with fiber Bragg grating Dandan Zhu, Zhiquan Li, Fu Sun, Xiuxian Tian, and Haifang Wang Proc. SPIE 6279, 627968 (2007); http://dx.doi.org/10.1117/12.725726 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Simultaneous strain and temperature measurement system with fiber Bragg grating was presented in this paper. The light from broadband source (BBS) was coupled into sensing probe through 3dB coupler1. Reflective light of two FBGs was split through coupler2 and went into chirped gratings with different pass-band. Demodulation method adopted chirped grating and long period grating edge linear filtering technology. It can send each reflected spectrum to different edge filter. It makes every FBG's reflective spectrum was demodulate. The central reflected wavelength of two FBGs was 1546.15nm and 1554.17nm respectively. Through simulation experiment, we can get that (formula available in manuscript). Strain measurement ranged from 0 to 2000 . Temperature measurement ranged from 0 to 200°C.

Select this Article		Research on character of fiber overcoupled devices Chunyu Liu and Hongan Ye Proc. SPIE 6279, 627969 (2007); http://dx.doi.org/10.1117/12.725728 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Utilizing the fused-taper technology, a fiber coupler with sensitive to wavelength and strain is obtained. This type coupler is fabricated after Nth coupling period. They are usually called overcoupled devices, N is the number of coupling period, N>>1. The relation between wavelength and coupling ratio of the coupler is analyzed. The maximum sensitive wavelength can be control by the fused-taper technology. When a Bragg wavelength of the fiber Bragg grating (FBG) is agreed with the maximum sensitive wavelength of the coupler, the shift of the Bragg wavelength is can be detected. In this paper we demodulate one FBG which Bragg wavelength is at 1564.69 with the coupler. So the coupler with sensitive to wavelength can be used to demodulate the FBG. And the sensitive to strain of the coupler is also analyzed. The experimental data is present as the theory value, sinusoidal curve. So the coupler can also be used to detect the strain and the temperature with the packaging of the thermal sensitive. The overcoupled couplers have a potential application to the sensing system.

Select this Article		Application research on optical grating in fiber gyroscope Ping Wang, Ke-jia Wang, Yue-jin Zhao, and Yi Wang Proc. SPIE 6279, 62796A (2007); http://dx.doi.org/10.1117/12.725730 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The paper proposes a scheme that utilizes phase-shifted fiber gratings technology to proceed to annual fiber gyroscope detection. As sharpness of resonance and polarization influences, the fineness of annual fiber gyroscope detective sensitivity gets limit. The solution method is to use the phase-shifted fiber grating to compress breathe of frequency. It can enhance sharpness of resonance, improve detective sensitivity and weaken parasitic interference influence. It is proved that phase-shifted fiber gratings play an important role to annular fiber gyroscope detective sensitivity validity and polarization weak influence. The scheme breaks a new path that enhances annual fiber gyroscope performance and predigests detective system.

Select this Article		High-precision optical fiber liquid-level sensor based on a sensitive and extrinsic Fabry-Perot interferometric cavity Tao Lü and Desen Liu Proc. SPIE 6279, 62796B (2007); http://dx.doi.org/10.1117/12.725735 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel intensity-based optical fiber liquid-level sensor based on a sensitive and extrinsic Fabry-Perot (F-P) interferometric cavity is described in this paper. The novel sensing schemes combines the advantages of both interferometry sensors and intensity-based sensors. The sensor operates on a single fiber F-P interferometric cavity with a DFB-LD light source. The elastic silicon slice replaces conventional reflected multimode optical fiber in extrinsic optical fiber F-P sensor as sensing element. Several steps have been taken to eliminate or restrain temperature effect influencing on the sensing system. Experimental results indicate a precision as high as 1.2mm of a full scale 3.5m (water) is obtained. The optimized sensor can be used in explosive and flammable environment to measure liquid-level continuously and accurately.

Select this Article		High power LD-end-pumped Nd:YVO₄ laser as a pump source for Raman fiber laser Chaohong Huang, Wencai Huang, Zhengqian Luo, Guoyong Sun, and Zhiping Cai Proc. SPIE 6279, 62796C (2007); http://dx.doi.org/10.1117/12.725738 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A LD-single-end-pumped Nd:YVO₄ CW all-solid-state laser with maximum output power 12.5W at 1064nm was designed to pump the cascaded phosphosilicate fiber Raman laser. The Nd:YVO₄ laser is lower in cost than Yb-doped cladding fiber laser which is usually used as a pump for Raman fiber laser. However, it is inefficient to couple pump beam into single mode fiber (SMF). The coupling efficiency from pump beam to SMF is largely affected by the beam quality. Thus, a high coupling efficiency requires maintaining laser's operation in the TEM₀₀ mode while scaling the power. The beam quality and maximum output power of the Nd:YVO₄ laser is restricted by the thermal lens and fracture within the gain medium under high pump intensity conditions. The thermal effects was decreased by using a 3×3× 10mm³ Nd:YVO₄ crystal with a low neodymium-doped concentration (0.3at%). Furthermore, a plane-plane resonant cavity with large mode volume and a large pump size was also used to reduce the effects. The Nd:YVO₄ laser with maximum output power 12.5W and M²<1.2 was obtained. More power than 4W was injected into cascaded Raman cavity at the maximum pump power and about 1W coherent second-order Stokes radiation at 1484nm was achieved.

Select this Article		Hi-bi-nlcfbg and hi-bi-ufbg used to compensate all-orders pmd Xianjie Feng, Cuimei Li, and Lan Chen Proc. SPIE 6279, 62796D (2007); http://dx.doi.org/10.1117/12.725740 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The first- and second- and third-order polarization mode dispersion has become a critical issue for high-data-rate optical systems. This paper advance a two-stages PMD compensator, which are made of a long length of Hi-Bi-NLCFBG(high-birefringence nonlinearly chirped fiber Bragg gratings) and a short length of Hi-Bi-FBG(high-birefringence uniform fiber Bragg gratings). The first stage adopts a Hi-Bi-NLCFBG[1], which been used compensated the first- and second- orders PMD, and the second-stage adopts a Hi-Bi-FBG, which used for third-order PMD compensation, respectively. Based on the numerical simulations, the spectrum characteristics and time delay of Hi-Bi-NLCFBG is investigated, then, we put forward that the amount of compensated PMD is proportion to length of Hi-Bi-NLCFBG, double-mode refraction index difference of highly birefringence fiber for the first time. Also, we modify a formula aiming to former literature; It is suggested that the value of first-chirped coefficient of Hi-Bi-NLCFBG must be suitable, or else, the effect of compensated PMD is bad. Subsequently, the differential group delay (DGD) of NLCFBG of normal polarization-mode of the single-polarization fiber is analyzed by means of numerical simulation, and we also analyzed the PMD of NLCFBG UV-writing leak-mode of the SP-SMF (Single Polarization Single Mode Fiber) In order to compensated the third-order PMD, we investigate the out-of-band time-delay of UFBG on the SP-SMF at the end of this paper.

Select this Article		Optical forces on a microscopic object of dual-beam optical fibers Ailing Tan, Yong Zhao, Jinshan Shi, and Yuefeng Qi Proc. SPIE 6279, 62796E (2007); http://dx.doi.org/10.1117/12.725742 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We studied the optical forces acting on a microscopic object generated by the laser beams from lensed optical fiber ends to research the parametric influence on the optical trapping. From these investigations, we verified that there was only one stable point of equilibrium located below the beam-crossing point, and revealed that the radius of a hemispherical microlens of an optical fiber end, the horizontal distance between each optical fiber end and the particle size are important parameters for strong three-dimensional trapping without physical contact.

Select this Article		Study on ameliorating the FEC coding techniques in current high-rate optical transmission systems Jianguo Yuan, Wenwei Ye, Ze Jiang, Youju Mao, and Wei Wang Proc. SPIE 6279, 62796F (2007); http://dx.doi.org/10.1117/12.725744 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, the three ameliorated new coding schemes of the Super-FEC (Forward Error Correction) concatenatedcodes (namely, the inner-outer concatenated-code, the parallel concatenated-code and the successive concatenated-code with interleaving) are proposed after the development trend of high-rate optical transmission systems and the defects of the FEC codes in the current optical transmission systems have been analyzed. The system simulation of the inner-outer concatenated-codes is implemented and the schemes of encoding/decoding the parallel concatenated-codes are proposed. Furthermore, the two successive concatenated-codes with interleaving of the RS(255,239)+RS(255,239) code and the RS(255,239)+RS(255,223) code are simulated, and the analyses for the simulation results show that the two successive concatenated-codes with interleaving, compared with the classic RS (255,239) code and other codes, are a superior code type with the advantages of the better correction error, moderate redundancy and easy realization. And their net coding gains (NCG) are respectively 1.5dB, 2.5dB more than that of the classic RS(255,239) code at the BER (Bit Error Rate) of 10^-12. At last, based on the ITU-T G.709, the frame format of the new concatenated-code on applying in high-rate optical transmission systems is proposed and designed, this lays a firm foundation in order to design its hardware in future and pioneers a direction in its physical application.

Select this Article		2D and 3D multiple optical tweezers Yue-feng Qi, Wei-hong Bi, and Ai-ling Tan Proc. SPIE 6279, 62796G (2007); http://dx.doi.org/10.1117/12.725751 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this article, we present the way how to generate an interference field created by two or three beams having their optical axes in one plane, therefore got the so called 2D interferometric optical tweezers. Firstly, we analyzed the arrangement where two co-propagating laser beams intersect at an angle and interfere there, the fringes so produced behave as an array of two-dimension multiple optical tweezers. Then we quantified the property of these traps by analyzing the forces exerted on the polystyrene beads. The last, we added the third counter-propagating beam that balanced the radiation pressure of the other two beams but did not interfere with them. Through this method, we can confine polystyrene beads at a given distance between the two surfaces of the sample cell. This also can be called the 3D traps. We also theoretically compared the lateral optical trap forces between 2D and 3D tweezers.

Select this Article		Analysis of amplifier spontaneous emission noise in Raman fiber amplifiers Zehua Hong, Zhihui Gao, Aihua Yu, and Bichang Huang Proc. SPIE 6279, 62796H (2007); http://dx.doi.org/10.1117/12.725752 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper temperature dependent models have been proposed that accurately describe amplified spontaneous emission in discrete and distributed Raman amplifiers. Using those models we analyzed a few main factors which influence the amplified spontaneous emission (ASE) noise. Rayleigh scattering that can enlarge the power of ASE noise is taken into consideration. So we have got a more accurate result.

Select this Article		Influence of two-photon absorption and optical excitation size on the THz radiation via optical rectification Liying Lang, Xiannong Wang, Xueguang Wang, Qirong Xing, Lu Chai, and Qingyue Wang Proc. SPIE 6279, 62796I (2007); http://dx.doi.org/10.1117/12.725739 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Although the ZnTe crystal used the generation of THz radiation has a favorable phase matching properties at 820nm, it has strong third-order nonlinearity, such as two-photon absorption effect. And we found experimentally that, the effect of two-photon absorption in ZnTe on the THz radiation was not neglect. In addition, due to optical rectification and diffraction effect, the generated efficiency of THz radiation is also related to the optical excitation size in the emitter. In this paper, by taking into account optical rectification, diffraction and two-photon absorption effects, the theoretical model is established to describe the emitting field intensity of THz radiation. There is excellent agreement between the theoretical results and the experimental data. The good agreement demonstrates that there is a trade-off between these three effects for THz radiation.

Select this Article		Design and optimization of a high-power L-band ASE fiber source Xiulin Wang, Chaohong Huang, Wencai Huang, Huiying Xu, Zhiping Cai, and Chenchun Ye Proc. SPIE 6279, 62796J (2007); http://dx.doi.org/10.1117/12.725741 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Two kinds of configurations of L-band amplified spontaneous emission (ASE) source with two-stage EDF and dual forward pumps are suggested for generating a high power L-band ASE spectrum. The characteristics are theoretically compared in terms of the output power, pumping conversion efficiency, bandwidth, and mean wavelength stability for these two configurations. The EDF length and pump power allotment are also optimized. An L-band ASE source of 76mW output power with about 36.2% pumping conversion efficiency are experimentally obtained.

Select this Article		Static modeling for membrane deformable mirror used in high-power laser Peng Wu, Haiqing Chen, Jie Li, and Hongbin Yu Proc. SPIE 6279, 62796K (2007); http://dx.doi.org/10.1117/12.725743 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The technology of membrane deformable mirror (DMs) that has the potential to achieve comprehensive wavefront compensation and control in high power laser has been developed rapidly in recent years. Experimental results reveal that strong nonlinearity is induced to the deformation of DMs with respect to the square of input voltage when operating voltage is more than 120V. The nonlinear response and strong coupling effect of control channel in DMs make it difficult to obtain the desired mirror surface shapes. A test bed is built up to measure the deformation of DMs driven by specified voltages. An efficient nonlinear model of deformation with respect to input voltages is presented using a back propagation neural network (BPNN). Deformation due to arbitrary actuator voltages applied to actuators to correct wavefront aberration can be calculated directly with a higher precision using the BPNN model proposed. The residual relative error of the proposed model shows the improvement of accuracy of an order about 5 as compared to that of linear model, and with no significant increase of time consumption. A preliminary open-loop control experiment of laser wavefront compensation is performed to exam the validity of applying the proposed BPNN model in laser wavefront compensation application.

Select this Article		Application of Monte Carlo simulation in airborne modulated lidar for bathymetric detection Dan Tan, Kecheng Yang, Jun Liang, Min Xia, and Jingsong Liu Proc. SPIE 6279, 62796L (2007); http://dx.doi.org/10.1117/12.725745 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The sensitivity of lidar (light detection and ranging) and the contrast of immersed targets are strongly reduced by the volume backscattering clutter. To overcome this shortcoming it has been proposed to use a microwave modulation in association with an optical carrier at 532nm, which is called modulated lidar. This paper develops a Monte Carlo simulation for application of modulated pulse lidar (light detection and ranging) in bathymetric measurements. First, modulated light pulse propagation in ocean water is simulated by a Monte Carlo model. Second, the echo signal is processed by advanced mathematical tools like cross-correlation and numerical filtering. The simulation results reveal the capability of the modulation approach in suppressing the water backscattering and enhancing the target contrast for the bathymetric field. Furthermore, more simulation experiments are performed with various ocean depth to study the detection performance in different environment. Details of this simulation model, in addition to the simulation results are presented.

Select this Article		Optical measurement methods of Dragon-I accelerator Guojun Yang, Zhuo Zhang, and Sifu Chen Proc. SPIE 6279, 62796M (2007); http://dx.doi.org/10.1117/12.725746 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Optical methods have many advantages in the beam measurement of particle accelerators. We use transition radiation and Cerenkov Radiation to measure the beam of Dragon-I linear induction accelerator. Beam profile, beam emittance, beam energy and energy dispersion are measured with the help of these radiations.

Select this Article		Annular photonic crystal defect mode for operation of single-mode laser Tian-bao Yu, Ming-hua Wang, Xiao-qing Jiang, and Jian-yi Yang Proc. SPIE 6279, 62796N (2007); http://dx.doi.org/10.1117/12.725748 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In analogy to the impurity levels of semiconductors, optical cavities are created if irregular regions are introduced into the perfect photonic crystals. Photonic crystal single defect cavity is expected to obtain nearly thresholdless laser because it can create wavelength-scale small resonant mode with high-quality factors and high spontaneous emission coupling. In this paper, we have studied a new type of defect called annular microcavity created by drilling a circular hole in a usual defect cylinder in two-dimensional triangular photonic crystal by using the supercell method. The hole within the rod greatly modifies the defect modes by controlling filling fraction of dielectric material from the inner of the defect and lowering symmetry of the defect. It is found that the annular defect provides extra two more variables due to the hole (radius and refractive index) that can be utilized to alter the properties of the defect. And this opens up a new method to achieve and tune acceptor-mode cavity. Moving the hole can split the degenerate modes. The departure displacement determines the splitting space and the departure angle determines symmetry of distributions of electric fields. These results exhibit more advantages over the conventional defects and may be utilized to single-mode operation of microcavity laser.

Select this Article		Hollow-core optical fiber for terahertz wave propagation Bing Zhang and Rong-jin Yu Proc. SPIE 6279, 62796O (2007); http://dx.doi.org/10.1117/12.725750 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The possibility of using a hollow-core Bragg fiber with cobweb-structured cladding to obtain low-loss transmission in terahertz (THz) frequency range is proposed and analyzed. Leaky losses of the fiber are analyzed as a function of the structure parameters for hollow-core Bragg fiber with cobweb cladding, such as number of alternating layers, core radius and width of air layer by an asymptotic matrix formalism. An estimate of the transmission losses of such fibers in longwavelength and short-wavelength range of THz wave is given. The results show that the transmission losses of the hollow-core Bragg fiber with cobweb cladding are far less than those of other fibers for THz wave reported so far in the literature.

Select this Article		The research on the photo-electronic integrated acceleration seismic detecting technology Zhengrong Tong, Jianxia Wei, De En, Caihe Chen, Yuming Cui, and Chao Li Proc. SPIE 6279, 62796P (2007); http://dx.doi.org/10.1117/12.725753 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract For high resolution application in seismic detection, the geophone should be smaller in size, more reliable and sensitive. So a kind of photo-electronic integrated acceleration seismic detecting technology, which is novel and precise based on waveguide M-Z interference, is presented. The principle of the photo-electronic integrated acceleration seismic geophone is introduced in this paper. The seismometer is composed of a waveguide M-Z interferometer, a sensing element, a modulation LD and signal processing system. The silicon crystal is adopted as the substrate. The core of the photoelectronic integrated acceleration is the silicon harmonic oscillator, which is supported by four silicon beams and integrated on the signal beam of the M-Z interferometer . The harmonic oscillator translates the acceleration information of the external vibrational signal into phase variation of optical signal in the sensing arm, which is converted into optical signal by M-Z interferometer, then PIN converts the optical signal into electric signal to process by the signal processing. The experimental curve of seismometer frequency response is achieved.

Select this Article		ECLD at 1.5μm with acetylene saturated-absorption frequency stabilization Jie Jin, Li Chen, Jin-wei Zhang, Yu Yang, and Xiang Ma Proc. SPIE 6279, 62796Q (2007); http://dx.doi.org/10.1117/12.725754 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The frequency-stabilized laser in 1.5m region is vital important for high capacity Dense Wavelength Division Multiplexing (DWDM).The acetylene (C2H2) saturated absorption frequency stabilization can be used to stabilize the frequency of laser in 1.5m region. A fiber grating external cavity semiconductor laser diode(ECLD) was designed according to the method of frequency stabilization, which used step motor to strain the fiber grating to tune the wavelength, and modulated the power of light by modulating the injecting current. The effect of frequency stabilization was authenticated by experiment.

Select this Article		Investigation of solid-state lasers aberration compensation using an intra-cavity adaptive optic mirror Zhengang Yang, Haiqing Chen, Jiafeng Chen, and Lei Wang Proc. SPIE 6279, 62796R (2007); http://dx.doi.org/10.1117/12.725759 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Thermal induced distortion in the gain element is the main obstacle to be overcome in the scaling of solid-state lasers to very high output powers. The resultant distorted thermal lens cannot be compensated for by cavity design alone. The investigation of the possibility to influence on the output beam parameters of a solid-state laser by methods of intracavity adaptive optics was carried out. An adaptive optic mirror has been used intra-cavity to control the output power of a solid-state laser. Power and beam profiles optimization are demonstrated by closed loop automatic optimization of the deformable mirror.

Select this Article		Weighted least squares phase unwrapping based on the wavelet transform Jiafeng Chen, Haiqin Chen, Zhengang Yang, and Haixia Ren Proc. SPIE 6279, 62796S (2007); http://dx.doi.org/10.1117/12.725761 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The weighted least squares phase unwrapping algorithm is a robust and accurate method to solve phase unwrapping problem. This method usually leads to a large sparse linear equation system. Gauss-Seidel relaxation iterative method is usually used to solve this large linear equation. However, this method is not practical due to its extremely slow convergence. The multigrid method is an efficient algorithm to improve convergence rate. However, this method needs an additional weight restriction operator which is very complicated. For this reason, the multiresolution analysis method based on the wavelet transform is proposed. By applying the wavelet transform, the original system is decomposed into its coarse and fine resolution levels and an equivalent equation system with better convergence condition can be obtained. Fast convergence in separate coarse resolution levels speeds up the overall system convergence rate. The simulated experiment shows that the proposed method converges faster and provides better result than the multigrid method.

Select this Article		Experimental study on period doubling of multiple quantum well Fabry-Perot laser Yue-peng Zhao, Ming-jiang Zhang, Yi An, and Yun-cai Wang Proc. SPIE 6279, 62796T (2007); http://dx.doi.org/10.1117/12.725762 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We experimentally study the period doubling phenomenon of gain-switched multiple quantum well Fabry-Perot laser diodes with/without external optical injection. The relations between resonance frequency and modulation frequency are analyzed detailedly when period doubling occurs. The obtained research results indicate that external optical injection may be an effective technique to suppress or enhance period doubling of a gain switched laser diode with injection optical power. Experiments show that the period doubling would appear in a broader frequency range with external optical injection, and indicate that period doubling occurs over a wide range of modulation frequency in laser diode as the injection power increases. Moreover, we have studied in detail that period doubling easily occurs when bias current is located between 1.1I_th and 1.3I_th, and modulation current is set between 0.5I_dc and 2.5I_dc.

Select this Article		Numerical analysis on the cooling characteristics of finite Nd: GGG slab in a solid state heat capacity laser Liqun Hou, Jifeng Zu, Yue Dong, Xianhua Yin, and Jianqiang Zhu Proc. SPIE 6279, 62796U (2007); http://dx.doi.org/10.1117/12.725763 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, based on the fundamental theories of heat transfer, we researched the cooling characteristics of a finite Nd: GGG slab working in HCL mode. The 3D thermal and stress fields in the slab are simulated by the ANSYS firstly, then distribution rules of temperature and stress are outlined, and the influences of coolant temperature and convective heat transfer coefficient on the cooling effects are also discussed. At last, a cooling method with increasing continuously flow rate coolant in normal temperature is proposed. As a result, the maximum cooling stress could be depressed down about ten percents and cooling procedure is also shortened. It can be suitable to some special SSHCLs' applications that have higher demand for cooling time.

Select this Article		CW and tunable laser operation of Yb³⁺ doped Gd_0.2Y_0.75(BO₃)₄ Y. H. Xue, Q. W. Liu, J. Li, L. Chai, J. Y. Wang, and Q. Y. Wang Proc. SPIE 6279, 62796V (2007); http://dx.doi.org/10.1117/12.725765 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract As self-frequency-doubled (SFD) lasers are potentially more compact and less costly, the novel high efficient SFD lasers attract great interest. Here we report the spectroscopic properties under room temperature of a new self-frequency-double Yb³⁺ doped Gd_0.2Y_0.75(BO₃)₄ (Yb:GdYAB) single crystal grown in Shandong University. Both foundation and self-double-frequency continuous-wave laser were operated with a high-power diode. A foundation laser slope efficiency of 82% with respect to the absorbed 975 nm pump power of 2.62 W was obtained. The center wavelength at 1040nm was generated and the laser wavelength could be tuned from 1020 to 1064 nm. And thus, the broadly emission spectra was advantageous for the production of short-pulse diode-pumped solid state lasers. Self-double-frequency green light was also obtained under pump power of only 274mW with a flat-concave cavity. The maximal output power was 330mW when pumped power was 2.62 W. A diode-to-green optical conversion efficient of 12.6% was achieved. The results demonstrated that the Yb:GdYAB crystals are potential candidates for efficient microchip both 1 m and visible laser media.

Select this Article		Artificial retina model for the retinally blind based on wavelet transform Yan-an Zeng, Xin-qiang Song, Fa-gang Jiang, and Da-ding Chang Proc. SPIE 6279, 62796W (2007); http://dx.doi.org/10.1117/12.725795 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Artificial retina is aimed for the stimulation of remained retinal neurons in the patients with degenerated photoreceptors. Microelectrode arrays have been developed for this as a part of stimulator. Design such microelectrode arrays first requires a suitable mathematical method for human retinal information processing. In this paper, a flexible and adjustable human visual information extracting model is presented, which is based on the wavelet transform. With the flexible of wavelet transform to image information processing and the consistent to human visual information extracting, wavelet transform theory is applied to the artificial retina model for the retinally blind. The response of the model to synthetic image is shown. The simulated experiment demonstrates that the model behaves in a manner qualitatively similar to biological retinas and thus may serve as a basis for the development of an artificial retina.

Select this Article		Accurate non-effective pixel detection and replacement based on multi-temperature matching Hui-ming Qu, Qian Chen, and Can-lin Zhang Proc. SPIE 6279, 62796X (2007); http://dx.doi.org/10.1117/12.725821 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The number and distribution of non-effective pixels is an important quality figure that defines a given infrared focal panel array (IRFPA). An accurate non-effective pixel detection algorithm is present in this paper. Through theoretical analysis of IRFPA responsivity suitable definition of non-effective pixel is given. Based on this definition an adaptive threshold is proposed to discriminate various non-effective pixels and normal pixels. Meanwhile, multi-temperature matching approach helps us to pick out the hided non-effective pixel under a certain temperature range. Finally, neighboring pixel interpolation is performed to substitute non-effective pixels according to spatial correlation. The benefit of this method is reducing misjudgment of non-effective pixels, which will degrade infrared image quality. This approach for detecting and replacing non-effective pixels is successfully applied to a set of frames obtained from an IRFPA imaging. Results show that the detection and replacement accuracy of non-effective pixels is greatly improved by this approach. Furthermore, the proposed algorithm is adaptable to a variety of non-effective pixel types.

Select this Article		A novel imaging method for photonic crystal fiber fusion splicer Weihong Bi, Guangwei Fu, and Xuan Guo Proc. SPIE 6279, 62796Y (2007); http://dx.doi.org/10.1117/12.725825 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Because the structure of Photonic Crystal Fiber (PCF) is very complex, and it is very difficult that traditional fiber fusion splice obtains optical axial information of PCF. Therefore, we must search for a bran-new optical imaging method to get section information of Photonic Crystal Fiber. Based on complex trait of PCF, a novel high-precision optics imaging system is presented in this article. The system uses a thinned electron-bombarded CCD (EBCCD) which is a kind of image sensor as imaging element, the thinned electron-bombarded CCD can offer low light level performance superior to conventional image intensifier coupled CCD approaches, this high-performance device can provide high contrast high resolution in low light level surveillance imaging; in order to realize precision focusing of image, we use a ultra-highprecision pace motor to adjust position of imaging lens. In this way, we can obtain legible section information of PCF. We may realize further concrete analysis for section information of PCF by digital image processing technology. Using this section information may distinguish different sorts of PCF, compute some parameters such as the size of PCF ventage, cladding structure of PCF and so on, and provide necessary analysis data for PCF fixation, adjustment, regulation, fusion and cutting system.

Select this Article		Effects of annealing on the photoluminescence of terbium-doped zinc oxide nanocrystalline Guo-li Song and You-Tong Yang Proc. SPIE 6279, 62796Z (2007); http://dx.doi.org/10.1117/12.725829 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Terbium-doped zinc oxide nanocrystalline are successfully prepared by Sol-Gel process at various annealing temperature from 400°C to 800°C. Photoluminescence spectrum (PL), Photoluminescence spectrum excitation(PLE) and X-ray diffraction pattern(XRD) of nanocrystalline ZnO:Tb³⁺ with excitation wavelength 368nm are measured at room temperature. XRD pattern indicates that nanocrystalline ZnO:Tb³⁺ has a hexagonal wurtzite structure and polycrystalline. The mean grain size of nanocrystalline ZnO:Tb³⁺ was 8nm~12nm calculated by Debye-Scherrer formula. Emission from ⁵D₄→⁷F₆ (485nm), ⁵D₄→⁷F₅ (544nm), ⁵D₄→⁷F₄ (584nm) and ⁵D₄→⁷F₃ (620nm) of Tb³⁺ ions, and wide visible band of ZnO were observed. Relationship between Photoluminescence intensity of the peaks of nanocrystalline ZnO:Tb³⁺ and annealing temperature were given, it was found that the optimal dopant concentration and annealing temperature was 4at% and 600°C. The luminescence process of Tb³⁺-doped zinc oxide nanocrystalline has investigated by using PL, PLE and XRD. Photoluminescence mechanism suggests that there is energy transfer between ZnO nanocrystalline hosts and the doped Tb³⁺ centers.

Select this Article		Range finding with chaotic laser train generated from laser diode with optical feedback Anbang Wang and Yuncai Wang Proc. SPIE 6279, 627970 (2007); http://dx.doi.org/10.1117/12.725838 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Range finding with continuous-wave chaotic laser train generated from laser diode with optical feedback is investigated theoretically. Chaotic laser is split into probe beam flighting to target and reference beam, and then, the distance of target can be calculated from the flight time obtained by correlating the time-delayed probe beam with the reference one. Effects of noise and waveform error on correlation performances for different chaotic states are investigated to study the system tolerance of environmental noise. Simultaneously, the effects of chaotic state characterized by the largest Lyapunov exponent and correlation dimension on correlation performances are demonstrated theoretically to select satisfying chaotic laser used as probe light. Simulated results indicate that ideal chaotic laser train should have high dimension and have smooth spectrum with broad bandwidth for ranging with high resolution. For the simulated system, ranging resolution within 1.5cm range independent of target location can be achieved using the chaotic lasers generated in middle of the chaos-generated regime of feedback level.

Select this Article		Photochromic diarylethenes for two-wavelength optical recording Shouzhi Pu, Fushi Zhang, and Gang Liu Proc. SPIE 6279, 627971 (2007); http://dx.doi.org/10.1117/12.725840 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract We have carried out successfully two-wavelength photon-mode optical storage using photochromic diarylethene materials, 1,2-bis(2-methyl-5-(2-(1,3-dioxolane))-thien-3-yl)perfluorocyclopentene (1a) and 1,2-bis(2-methyl-5-(2,2'- dicyano-vinyl)-thien-3-yl)perfluorocyclopentene (2a), as recording medium. Two laser beams of 532 and 780 nm were used in recording and readout simultaneously, and signals with high S/N ratio were obtained. The results showed that the two diarylethenes had responded rapidly upon irradiation of the corresponding wavelength laser. The destruction of the readout and the photochromic properties of the two diarylethenes in PMMA film were also investigated.

Select this Article		Birefringence index-guiding photonic crystal fibers Shuqin Guo, Wensheng An, and Nian Fang Proc. SPIE 6279, 627972 (2007); http://dx.doi.org/10.1117/12.725847 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Based on typical triangular arrangement of air holes with equivalent diameter size, enlarging eight air holes of arranged in the diamond shape closing to the core of photonic crystal fiber (PCF) to form asymmetry structure of section, this kind of peculiar arrangement of air holes in inner-cladding can make modal field present some birefringence character and birefringence degree can be obtained at the magnitude of 10^-4. Here, a series of characters about designed PCFs, such as modal field, dispersion, effective refractive index in two orthogonal directions, and birefringence are investigated.

Select this Article		The exact validation for measuring the electro-optic coefficients of organic/inorganic hybrid material film Jie Sun, Weinan Gao, Alin Hou, Hongfei Liu, Maobin Yi, and Daming Zhang Proc. SPIE 6279, 627973 (2007); http://dx.doi.org/10.1117/12.725852 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Exact expressions for calculating the electro-optic (EO) coefficients of GaAs and polymer or organic/inorganic hybrid film using simple reflection technique have been deduced. For different approximate conditions, several expressions have been contrasted. After strictly verified, the measuring systems are accurately adjusted, and with the measured data the numerical value of ₃₃ can be calculated. The measured EO coefficient of GaAs is in excellent agreement with the known value. The organic/inorganic hybrid material is prepared by sol-gel process during which dispersed red 1 (DR1) is doped in tetraethoxysilane (TEOS) as the chromophore with a concentration of approximately 13% by weight. And ₃₃ of hybrid material over 20pm/V could be easily obtained.

Select this Article		The comparison of two kinds of fiber phase shifting point-diffraction interferometer Lingfeng Chen, Liang Nie, Taogeng Zhou, and Dingguo Sha Proc. SPIE 6279, 627974 (2007); http://dx.doi.org/10.1117/12.725886 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The point diffraction interferometer (PDI) is the technology which realizes the absolute interferometric measurement without the use of reference surface. Pinhole is mostly used to generate the ideal spherical wavefront traditionally. While using the single mode optical fiber instead of pinhole can easily introduce phase-shifting ability for PDI measurement. This paper mainly discusses the merits and disadvantages of two kinds of fiber phase shifting point diffraction interferometer (FPS/PDI). Two fibers FPS/PDI is a separated-path configuration. Although it's easy to adjust, it's more sensitive to environment influence, and the thickness of fiber cladding will induce an off-axis error during measurement. Single fiber FPS/PDI is a common-path configuration, thus it is robuster than the front, but the maximum visibility is now one half. Its accuracy is mainly affected by factors such as the fiber core diameter, slight ellipticity and oblique face. The paper lastly compares the single fiber PDI with ZYGO interferometer based on measurement data about a sphere surface, the single interference pattern collected by our experimental fiber PDI apparatus is analyzed and the major error sources are also discussed.

Select this Article		Shape effect on nonlinear optical properties of CdS nanorod and nanoparticle films Wenjie Gong, Qing Chang, and Yinglin Song Proc. SPIE 6279, 627975 (2007); http://dx.doi.org/10.1117/12.725891 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The third order nonlinear optical properties of CdS nanorod film and CdS nanoparticle film were investigated comparatively by using nanosecond laser pulses at 532 nm. It is observed that the values of the nonlinear refractive index n₂ (23×10^-11 esu), the nonlinear absorption coefficient β (4.4×10^-11 m/W) and the effective third order nonlinear susceptibility ) χ⁽³⁾_eff (1.7×10^-11 esu) of CdS nanorod film are larger than CdS nanoparticle film (5.2×10^-11 esu, 3.9×10^-11 m/W, 1.4×10^-11 esu). Experimental results show that the shapes of CdS nanomaterials have effect on their third order nonlinear optical properties. The results were analyzed by use of the Maxwell-Garnett Effective Medium theory (MGT).

Select this Article		A novel microstructured optical fiber with high birefringence Bingxin Li, Dongmei Hu, Baorong Zhang, and Rongjin Yu Proc. SPIE 6279, 627976 (2007); http://dx.doi.org/10.1117/12.725900 \| Cited 1 time Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract High birefringence optical fibers such as elliptical core fibers and many highly birefringent photonic crystal fibers usually broke the symmetry of circle by introduced C_2ν symmetry. In this paper, a novel microstructured high birefringence optical fiber with C_1ν symmetry is proposed. Four air holes were introduced into the core of a circular optical fiber, circular symmetry was broken, and the core of this kind of optical fibers only maintained C_1ν symmetry. The degeneracy fundamental mode LP₀₁ was split into two modes LP^x₀₁, LP^y₀₁ because the symmetry of C_1v is lower than that of C_2ν , the difference between the patterns of the two modes field was larger. Using multipole method, we calculated the propagation constants of modes LP^x₀₁ and LP^y₀₁, the modal birefringence B is to the magnitude of 10^-2 which is almost tenfold greater than that of many highly birefringence photonic crystal fibers. The other advantage of this kind of optical fibers is that the fabrication of fibers with a few air holes is easier than that of photonic crystal fibers with many air holes.

Select this Article		The evolution of polarization state in two-mode optical fibers Baorong Zhang, Dongmei Hu, Bingxin Li, and Dezhong Zheng Proc. SPIE 6279, 627977 (2007); http://dx.doi.org/10.1117/12.725925 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Two-mode optical fibers have been studied extensively for telecommunication device and sensor application. This paper investigates the evolution of polarization state in two-mode optical fibers. Two-mode Fibers usually support four modes, i.e. LP^x₀₁, LP^y₀₁, LP^x₁₁(even), LP^y₁₁(even). The propagation constants of the four modes are different so that the polarization state of an incident light will not maintain when the light propagating along the fiber. The evolution of the polarization state in a two-mode optical fiber is analyzed in theory, the result shows that unlike a conventional highly birefringent optical fiber, the polarization state of the incident light is not recurred at any length of the fiber; i.e. strictly speaking, the beat length is not existed in a two-mode optical fiber. However, the every modal birefringence index of two modes can be found by a wavelength scanning method. The power of the output light in a special polarization direction is detected; it is a multi-cycle function, which depends on the wavelength of the incident light. Six periods can be given by using the Fourier transform spectrum of the output light; they are in direct proportion to modal birefringent indices and the fiber length, so three modal birefringence indices can be got. It is a most important property of the two-mode optical fibers for device and sensor application.

Select this Article		Experimental investigation of the fringe pattern of capillary tube filled with liquid by using focused laser sheet of light Ailing Yang, Wendong Li, Junyu Dong, Guimei Sun, Decang Bi, Guang Yuan, and Jinliang Zhang Proc. SPIE 6279, 627978 (2007); http://dx.doi.org/10.1117/12.725931 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A focused laser light sheet was used to illuminate the capillary tube filled with liquid and fringe patterns can be seen. The fringe patterns can be formed by rays directly passing through the capillary tube or reflected one time or two times by the walls of the capillary tube then transmitted again. The fringe patterns formed by transmission light lie before the capillary tube and can be bell-shaped, steep bell-shaped, or almost parallel, which strongly depend on the position of the capillary tube. The bell shaped pattern can be qualitatively explained by the addition of diffraction of multi-slits and is relative to the aberration of the cylindrical lens. This pattern is also relative to the refractive index of liquid containing in the capillary tube. The fringe patterns caused by reflected light lie before or after the capillary tube, which will influence the contrast of the bell shaped fringe pattern formed by transmitted light.

Select this Article		Design method of a binary optical element for collimation of high power LD beams with astigmatism Changqing Cao, Xiaodong Zeng, Yuying An, Yili Zheng, Juncheng Xu, and Meng Xie Proc. SPIE 6279, 627979 (2007); http://dx.doi.org/10.1117/12.725944 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Owing to its compactness, lightness, and low cost, laser diodes (LD) play an important role as a coherent source in various fields of technology. Because of the waveguide properties of their active areas, laser diodes generate large divergence-angle beams with elliptically shaped intensity profiles. And the beam of LD has astigmatism. So it is difficult to collimate LD beams effectively. The binary optical elements are small, light, easy to be copied and able to realize multi-purpose integrated, especially suits for the beam shaping of laser diode array. Based on accurate far-field model of high-power laser diode, a design method of binary optical element for laser diode beams, which can correct the astigmatism of the laser beam, has been developed, and the principle and process has been given in detail. The method is simple and practical. The relief surface of the element is of multiphase structure. And its theoretical diffraction efficiency is as high as 95%.

Select this Article		Research on surface topography of MEMS micromirror based on 3D Weierstrass-Mandelbrot function Yuan Luo, Yi Zhang, and Xiaodong Xu Proc. SPIE 6279, 62797A (2007); http://dx.doi.org/10.1117/12.725945 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Micro-mirror is the key structure of MEMS optical switch, Digital Mirror Display (DMD) and variable optical attenuators. Surface roughness plays a crucial rule in reflectivity, insertion loss, and all kinds of surface forces. In this paper, a silicon based non-silicon MEMS optical switch is fabricated and the topographies of various micro-mirror surfaces are measured by Scanning Tunneling Microscope (STM). After fractal analysis, a three-dimensional Weierstrass-Mandelbrot function is applied to simulate the topography of different surfaces. The result shows that the surface of MEMS micromirror which fabricated by metal sputter has low anisotropism and the W-M function is very efficient in creating models and is very useful in analysis the topography of MEMS surface.

Select this Article		A novel infrared mono-station passive location algorithm based on a mobile platform En-ke Li, Shi-min Yin, Shang-qian Liu, Xiao-ning Fu, Da-bao Wang, and Xing-guo Zhang Proc. SPIE 6279, 62797B (2007); http://dx.doi.org/10.1117/12.725946 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract A novel infrared mono-station passive location algorithm for a maneuvering target is presented based on infrared imaging, series images processing and three dimensional movement analysis. The algorithm results in the relative distance between the maneuvering target and the measurement station by using the measured information of infrared imaging target. It accurately reflects the actual situation of complex relative movement between the mobile target and the mobile measurement platform, effectively overcomes the bad influence of the gesture change in the target itself and the pseudo-gesture change in the target caused by the relative movement between the mobile measurement platform and the mobile target on ranging precision, objectively reflects the various actual states on the complex relative movement between the mobile measurement platform and the mobile target. It is applicable to such relative motion models between the maneuvering target and the maneuvering measurement station as the invariable velocity, invariable acceleration and variable acceleration and so on with high location precision, small cubage and great mobility. The correctness and validity of the algorithm are illustrated by both the computer digital simulation and the semi-practicality visible light imaging simulation. Under the conditions of satisfying the measurement precision requirements on the image and angle parameters of the target, the relative error of measuring distance is not larger than 5%. At the same time, the algorithm is also suitable for visible light mono-station passive location.

Select this Article		Damage in sensitive BSO-based asymmetric spatial light modulator Xiujian Li, Jiankun Yang, Juncai Yang, and Wenhua Hu Proc. SPIE 6279, 62797C (2007); http://dx.doi.org/10.1117/12.725949 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Some damages may occur when sensitive BSO (Bi₁₂SiO₂₀) asymmetric spatial light modulators operate in some given modes, even though the power of the writing light beam is far less than the optical damage threshold. According to some experimental results and corresponding analysis, high voltage and given operating modes may lead to too high intensity photocurrent pulse in short time, consequently large quantity of heat in ultra-small area may make the narrow areas swell up and thus the damage of the BSO film. In order to get well sensibility, well resolution and well response speed without damages of the spatial light modulators, optimizing the structure parameters and the operating modes is necessary.

Select this Article		Research on crop and weed identification by NIR spectroscopy Jiazhi Pan, Yueming Tang, and Yong He Proc. SPIE 6279, 62797D (2007); http://dx.doi.org/10.1117/12.725951 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Crop and weed identification is very importance in precision farming field. As spectroscopy can reflects the contents of object tested, so it is possible to identify crop and weed with high correct rate. ASD FieldSpec recorded the spectrum of crops and weeds. Its waveband is 325-1075nm and with resolution of 3.5nm. One crop seedling and three kinds of weeds living together were tested. Each species has at least 30 sampling spectrum taken down. As one sample spectrum has too much data, wavelet transform reduced the data volume firstly, which compressed source signals to tens of floating numbers from 751 floating numbers. Totally 160 samples were used to build a radial basis function neural network, the object output was a 4 by 1 dimension vector. Those left 43 samples used to check the identifying capability. As neural network model has huge power in solving these pattern recognition problems. It can approach to giving finite function at any approximation. Nearly all these predicting samples classified right. Therefore, by using spectroscopy in the identification is possible, and having high correct rate. Further more, the computation is very fast. Whereas the spectrometer is expensive and easily affected by shaking and variation of light shine, it cannot installed directly on vehicles at present time. In the future, it may be possible to recognize crop and weed in real time by using spectroscopy.

Select this Article		The theory analysis and experiment measure of lateral optical trapping force Yanying Zhu, Qiujuan Gao, and Yong Wei Proc. SPIE 6279, 62797E (2007); http://dx.doi.org/10.1117/12.725952 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract In non-equality optical field, we use the RO model, which is based on the theory of geometric optics, the optical trapping force which is in Y axes way on the micro sphere particles in the Mie scattering field is calculated quantitatively. The simulation results under given parameters are described. According to the simulation results, the relations between the optical trapping force and the main parameters of the system, including focus corset radius and the laser wave-length are discussed.

Select this Article		Large electro-optic effect in sol-gel-processed poled TiO₂/SiO₂ films doped with organic azo dye Alin Hou, Hongfei Liu, Shaolin Liu, Weinan Gao, Jie Sun, Daming Zhang, and Maobin Yi Proc. SPIE 6279, 62797F (2007); http://dx.doi.org/10.1117/12.725953 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Highly transparent TiO₂/SiO₂ films prepared using sol-gel technique doped with organic azo dye, Disperse Red 1(DR1) have been investigated. Processing parameters such as spin speed, spin time, and ambient atmosphere, and solution synthesis parameters such as catalysis method, alcohol dilution ratio, and component molar percentages, may affect the film formation. The refractive index increases follow along with the raising of the molar ratio between TiO₂ and SiO₂. When the molar ratio between TiO₂ and SiO₂ is zero, i.e. no titania precursor in the initial solution, the refractive index is minimum 1.49 at 1300nm, whereas when there is no TEOS in the initial solution, the refractive index is maximum 1.81 at 1300nm. The sol-gel thin film is spin-coated on ITO glass substrate with better uniformity. The electric-optic coefficient ₃₃=42pm/V was measured by simple reflection technique at a fundamental wavelength of 1300nm. The hybrid organic-inorganic sol-gel film is well balanced material in its simplicity for film formation, nonlinearity, and thermal stability sufficient for device fabrication. Moreover, the measurement system was calibrated and the measured electric-optic coefficient of the gallium arsenide crystal is in excellent agreement with the known value.

Select this Article		Novel optic fiber voltage sensor based on interference between modes Feng Liu, Weihong Bi, and Xuan Guo Proc. SPIE 6279, 62797G (2007); http://dx.doi.org/10.1117/12.725955 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract This paper investigates the principle of interference between modes in fiber, and gives the relationship between interference of LP₀₁ and LP₁₁^even mode and the axial length variety in ideal fiber. A novel scheme of voltage transducer based on interference between modes is brought out. A PANDA fiber wrapped quartz crystal sandwiched with two pieces of metal electrodes works as sensing interferometer. When voltage is applied on the metal electrode, circumference of quartz crystal will change. This can modulate the light path difference of LP₀₁ and LP₁₁^even mode in fiber. A receiving interferometer balances the light path difference with a fiber wrapped piezoelectric ceramics and a phase tracer. Control voltage of the receiving interferometer is output signal of the transducer. Simulation result and adjusting method of dynamic range is given in the paper. It can provide a new method for designing voltage transducers.

Select this Article		The study of optical trapping force from optical tweezers Yanying Zhu and Mingli Wang Proc. SPIE 6279, 62797H (2007); http://dx.doi.org/10.1117/12.725956 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Optical tweezers use the forces exerted by a strongly focused beam of light to trap and move objects ranging in size from tens of nanometers to tens of micrometers. Since their introduction in 1986, the optical tweezers has become an important tool for research in the field of biology, physical chemistry and so on. So the study and measure of optical trapping forces are important currently, and those are also helpful for the development of optical tweezers. At present the theoretical model has been established about the calculation method of optical tweezers. This document shows a method of optical tweezers on axis. The optical trapping force was measured and estimated in experiment. The theoretical model of optical trapping force on axis is different with different size particle. One is Mie particle which size is much larger than the laser wavelength. We can calculate the optical trapping force by the theoretical model based on geometrical-optics. Another is Rayleigh particle which size is much smaller than the laser wavelength. We can calculate the optical trapping force by the theoretical model based on electromagnetics. A method was presented mainly about the calculation of optical trapping force on axis in this document. Under given parameters, the numerical simulation of the optical trapping force on particle was demonstrated. And the important impacts of the parameters were discussed including the radius of the beam waist, the laser wavelength, the laser power, particle radius and so on. Through the numerical simulation, they have the close relation between the different system parameters and the optical trapping force. The optical trap will change shallow along with the radius of the beam waist increasing. On the contrary, the optical trap will change deep along with the laser power increasing. They have a best optical trap scope between the laser wave length and the particle radius. Thus, we can choose the appropriate parameters in the experiment to obtain the best optical trapping force. We captured and moved a particle by a strongly focused beam of laser in experiment. In order to obtain the escaping speed, we control platform steadily and record the entire capture process through the CCD imaging system. Figuring out the escaping speed from the known two time interval and the granule displacement value, we can estimate the optical trapping force by Stocks formula.

Select this Article		A scale distortion invariant pattern recognition with fractional matching filter correlation Jun Li, Bin He, Guang-zhi Fu, and Chun-hui Wang Proc. SPIE 6279, 62797I (2007); http://dx.doi.org/10.1117/12.725957 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Two optical units who are constructed by one Fresnel transform and one lens can produce a scale fractional Fourier transform. The constraints between the tow units are analyzed. Based on that and fractional correlation theory, a scale distortion invariant pattern recognition method is proposed. Simulation results show that when a scale distortion input image can't be rightly recognized by the conventional correlation, it can be recognized well with the method. Deficiency of the method is that lots of matching filters are needed.

Select this Article		Research on encode technology for aspherical surface measurement based on real-time hologram Hongjun Wang, Zhao Wang, Hong Zhao, and Ailing Tian Proc. SPIE 6279, 62797J (2007); http://dx.doi.org/10.1117/12.725958 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The aspherical measuring technology that based on computer-generated hologram (CGH) was introduced. The advantage of this method is that the phase shifts can be controlled digitally, no any mechanical moving and rotating element. By changing CGH coding which displayed on the Liquid Crystal Display (LCD), the wavefront and phase shifts in measuring system were induced. Based on the characteristics of aspherical measurement and LCD structure, the CGH encode technology used in LCD was discussed. Then a new encode method which applied to aspherical measurement was put forward. In this method, the LCD modulates functions of amplitude and phase was coexistent, and the character of LCD diffraction frequency spectrum was considered, and phase hologram was applied. This aspherical measuring technology is more flexible than usual method. In this paper, the hologram encode method based on LCD were illuminated in detail. In order to verify the correction of encode technology, the aspherical surface with standard wavefront was generated by coaxial hologram reconstruct system when hologram encode image was displayed on SONY LCX023 LCD, it interfere with the standard spherical wavefront, then the interferogram was sampled to computer by Charge Coupled Device (CCD) and A/D transfer, the wavefront of hologram reconstruct was obtained by image process finally. All calculation is completed by Matlab. An aspherical measuring system based on LCD was built experimentally. Both the theoretical analysis and experimental results demonstrate the feasibility of this approach.

Select this Article		A matching method based on valid invariant feature part Lichun Li, Xiaohu Zhang, Qifeng Yu, and Heng Zhang Proc. SPIE 6279, 62797K (2007); http://dx.doi.org/10.1117/12.725992 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The target tracking method based on correlation in image sequence is always invalid because of the magnitude or shape distortion and occlusion. In this paper a robust and highly accuracy matching algorithm called Matching Based on Valid Invariant Feature Part (MBVF) is proposed, which combines the target image invariant feature description, matching of feature, and recognition of valid feature. The feature descriptor is formed from a vector containing the values of all the grad magnitude and orientation entries that belong to the divided parts of target area. The features is robust to image rotation, distortion, addition of noise, change in 3D viewpoint, and change in illumination. The first step of the algorithm is to build the invariant feature descriptor of the target area in the referenced image. At the second step, a coarse position of the target is calculated using the traditional forecast and correlation method. And the invariant feature descriptors of all the possible points of the tracked target in image to be tracked are built also. Next, by comparing the invariant feature of the referenced target and the tracked target the valid feature parts of the feature are recognized. At last, similitude function is calculated according the valid feature parts in both images, which give the final fine position of the target in the tracked image. Experiment results show that the MBVF can deal with the target tracking and positioning problems in image sequence process and stereo image analysis automatically and accurately.

back to top

Poster Session: Opto-Mechanical High-Speed Cameras

Select this Article		Numerical prediction on static and dynamic properties for rotating mirror of ultra-high-speed photography Hongbin Huang, Jingzhen Li, Xiangdong Gong, Fengshan Sun, and Tiefeng He Proc. SPIE 6279, 62797L (2007); http://dx.doi.org/10.1117/12.725994 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The methods of numerical analysis for the strength and vibration modals of rotating mirrors were presented based respectively on the three-dimensional elastic mechanics and dynamics. On strength computation, the finite element models of rotating mirror were established according to the real structure of mirror, and the rotating three-faced aluminous and beryllium mirrors were analysed contrastively. Results display that the surface deformation quantity of the aluminous mirror is approximately 20 times as large as beryllium one, and the maximum stress is 1.6 times against the latter. Then, the three-faced aluminous mirrors were analyzed at variedly fit between shaft and axle hole. One conclusion is gotten out that the mirror strength is foreign to fits, but it is weaken by the axle hole obviously. On the modal analysis of vibration, this method can simulates accurately the natural frequencies and corresponding modalities of mirror. And the results from three-face aluminous mirror indicate that the resonance points of a new mirror may be guaranteed existing in selected speed range.

Select this Article		Numerical simulation on surface deformation for rotating mirrors of ultra-high-speed photography Hongbin Huang, Jingzhen Li, Xiangdong Gong, Fengshan Sun, and Bin Hui Proc. SPIE 6279, 62797M (2007); http://dx.doi.org/10.1117/12.725998 Online Publication Date: Jan 11, 2007 Full Text: \| Download PDF
	+ -	Show Abstract The numerical analysis method for the surface deformation of rotating mirrors were presented based on the three-dimensional elastic mechanics and the computational techniques of finite element in this manuscript. With this method, the surface deformation curves of rotating mirrors including multi-surfaces from three to eight, aluminous, steel, and beryllium ones were calculated. A result was obtained that surface patterns of a mirror in operation are primarily dependent on the amount of surfaces and the axial hole which whether or not exists for aluminous and steel mirrors, but it rests with the amount of surfaces as well as Poisson's ratio for a beryllium mirror with so tiny Poisson's ratio. This conclusion is different from that of forerunner.

back to top

Additional Papers

Select this Article		The granulated gold-film-based semitransparent photocathodes in the visible spectrum range for femtosecond time-resolution experiments E. L. Nolle, M. Y. Schelev, V. I. Lozovoi, N. D. Polikarkina, and N. S. Vorobiev Proc. SPIE 6279, 62797N (2007); http://dx.doi.org/10.1117/12.728648 Online Publication Date: Jan 17, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Developed is the granulated, Au film-based, semitransparent photocathode consisting of spherical Au nanoparticles. The granulated Au films are activated by a thin layer of cesium and oxygen of about two monolayer thicknesses to decrease the work function down to about 1 eV and gain the photoemission effect in the visible spectrum range. The sensitivity maximum equal to about one mA/W is located in the green spectrum range. The nanoparticles formation and photocathode surface structure are studied with the use of the X-ray photoelectron spectroscopy technique. Those studies have shown that the photoemission effect in the wavelength range λ> 450 nm is conditioned by excitation of the surface plasmons in quasi-spherical Au nanoparticles. This has allowed manufacturing of a streak tube with the introducible, Au nanoparticles-based photocathode, stability of which has been remaining invariant.

Select this Article		The results of computer and experimental studies on compressing the ultrashort photoelectron bunches with time-dependent electric fields Sergey A. Andreev, Gennadiy I. Bryukhnevich, Valentina P. Degtyareva, Dmitriy E. Greenfield, Valeriy Lozovoi, Mikhail A. Monastyrskiy, Mikhail Y. Schelev, Yuri N. Serdiuchenko, Victor A. Tarasov, and Nikolai S. Vorobiev Proc. SPIE 6279, 62797O (2007); http://dx.doi.org/10.1117/12.728650 Online Publication Date: Jan 17, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Some theoretical milestones, in definite sense summarizing our studies on temporal compressing of photoelectron bunch with time-depending electric fields, are elucidated. The recent experimental results on dynamic compression of photoelectron bunches of picosecond duration, gained with the use of a newly designed photoelectron gun employing the electric field ramp of about 1.5 kV/ns, are presented and compared with the results of computer simulation.

Select this Article		Numerical estimation of space-charge interaction in ultrashort electron bunches Dmitry E. Greenfield and Mikhail A. Monastyrskiy Proc. SPIE 6279, 62797P (2007); http://dx.doi.org/10.1117/12.728651 Online Publication Date: Jan 17, 2007 Full Text: \| Download PDF
	+ -	Show Abstract Space-charge interaction effect in ultrashort electron bunches is considered. It is shown that, along with the already known possibility of effective (first-order) temporal focusing, the time-depending electric fields offer the advantage of partial compensating for space charge effects in the bunch, which, in turn, seems most promising from the viewpoint of dynamic range increase in photoelectron tubes and diffractometers.

Select this Article		The up-to-date approaches to femto-attosecond photoelectron imaging M. Ya. Schelev Proc. SPIE 6279, 62797Q (2007); http://dx.doi.org/10.1117/12.728652 Online Publication Date: Jan 17, 2007 Full Text: \| Download PDF
	+ -	Show Abstract General overview of the past and present, and a look to the future of high-speed image-tube photography are presented. It is emphasized that it was in Russia that the truly first image-converter tubes were specially designed for the needs of high-speed photography more than half a century ago. In the middle of the fifties E.K Zavoisky and S.D. Fanchenko conducted the very first investigations of ultra-high frequency electrical discharge with experimentally reached and tested 10 ps time resolution, and theoretically predicted the 10 fs ultimate time resolution threshold for highspeed image-tube photography. Our own, almost half a century long, laser-oriented researches in this area have confirmed better than 100 fs time resolution in high-speed image-tube photography as well as theoretical possibility of photoelectron bunch compressing down to the sub-femtosecond level.

View presentations in solar, OLEDs, and more

Field Guide to Geometrical Optics

Join SPIE