The design & tolerancing of an optical testing system (OTS) presents a unique set of challenges not generally encountered during the typical optical design process. The authors have spent the past six years developing and using a series of optical systems designed to measure the surface figure & radius-of-curvature of various ultra-lightweight mirrors at 30 K. These mirrors were part of a technology development program to support NASA’s James Webb Space Telescope (JWST). The design of these systems required consideration of the following: (i) potentially large figure errors in the test mirror (due to gravity sag & cryo-distortion), (ii) cryo-shrinkage of the aperture and radius-of-curvature, (iii) figure changes due to the use of mirror actuators, and (iv) vibration between the OTS & the test mirror. In addition, an exhaustive tolerancing process was required for each system in order to reach a set of alignment tolerances that were achievable using the equipment available and within the test environment. The authors found many aspects of the OTS design process to be significantly different from the norm; at the same time, however, viewing the process as a typical optical design problem often-times brought clarification. This paper will describe both the differences and the similarities observed between the design of an OTS as opposed to a traditional imaging system.

New catadioptric objectives have been developed with large bandwidths in the DUV, high numerical apertures (NAs), and small size. This can be achieved using a single glass material. Designs are specifically optimized for loose alignment tolerances and ease of manufacturability. Applications include broad band DUV imaging and high resolution immersion imaging for industrial microscopy and life sciences.

We present details of optical design, opto-mechanical design and testing of a visible-NIR imaging optical system for a Fourier transform spectrometer dedicated to astronomical application at the Mont Megantic Observatory (Observatoire du Mont Megantic, OMM, located south Quebec city, Canada). Design considerations as well as testing and experimental results are presented.

An ultra-fast focal reducer design originally intended for use with spherical primary mirrors (published in Optical Engineering, February, 2003), has been adapted for use as a retro-fit for existing telescopes of ~2m pupil diameter that have aspheric mirrors. The focal reducer has only one aspheric surface, located at the aperture stop, and can provide speeds up to f/0.75 while maintaining a wide field with pixel-limited resolution and a broad spectral passband. Examples have been computed for Ritchie-Chretien, Dall-Kirkham and Cassegrain systems, and for use at the prime focus of mirrors with non-zero conic constants.

The Spaceborne Infrared Sounder for Geosynchronous Earth Orbit (SIRAS-G) represents a new approach to infrared imaging spectrometry suitable for Earth observation from geosynchronous orbit. SIRAS-G is currently being developed under NASA’s Instrument Incubator Program (IIP-4). SIRAS-G is an instrument concept with lower mass and power requirements than heritage instruments that offers enhanced capabilities for measuring atmospheric temperature, water vapor, and trace gas column abundances in a compact package. The flight instrument concept measures infrared radiation in 2048 spectral channels with a nominal spectral resolution (λ/Δλ) of 1400. The system employs wide field-of-view hyperspectral infrared optical system that splits incoming radiation to four separate grating spectrometer channels. Combined with large 2-D focal planes, this system provides simultaneous spectral and high-resolution spatial imaging. In 1999, the SIRAS team built and tested the SIRAS LWIR Spectrometer (12.0 - 15.4μm) under NASA’s Instrument Incubator Program (IIP-1). SIRAS-G builds on this experience with a goal of producing a laboratory demonstration instrument including the telescope, a single spectrometer channel, focal plane and active cooling subsystem. In this paper, we describe the on-going development of this laboratory demonstration instrument, including design, performance requirement predictions, and potential future scientific instrument applications.

The Orbiting Carbon Observatory (OCO) will measure the distribution of total column carbon dioxide in the Earth's atmosphere from an Earth-orbiting satellite. Three high-resolution grating spectrometers measure two CO2 bands centered at 1.61 and 2.06 μm and the oxygen A-band centered at 0.76 μm in the near infrared region of the spectrum. This paper presents the optical design and highlights the critical optical requirements flowed down from the scientific requirements. These requirements necessitate a focal ratio of f/1.9, a spectral resolution of 20,000, and precedence-setting requirements for polarization stability and the instrument line shape function. The solution encompasses three grating spectrometers that are patterned after a simple refractive spectrometer approach consisting of an entrance slit, a two-element collimator, a planar reflection grating, and a two-element camera lens. Each spectrometer shares a common field of view through a single all-reflective telescope. The light is then re-collimated and passed through a relay system, separating the three bands before re-imaging the scene onto each of the spectrometer entrance slits using an all-reflective inverse Newtonian re-imager.

Satellite-based remote sensing offers the best opportunity for studying the properties of atmospheric aerosols and their radiative effects on the global scale over extended periods Tropospheric aerosols represent the largest uncertainty in predicting the radiative forcing of climate (IPCC, 2001). A key question is whether atmospheric aerosols contribute to warming or cool the climate system. Since the sign of direct radiative forcing is controlled by the ability of aerosol particles to absorb light, the information on the single scattering albedo of different aerosol types and its variations with aerosol lifecycles is clearly very desirable. Furthermore, the wavelength-dependent values of single scattering albedo from the UV to IR are important in retrieving aerosol optical depth from satellites passive remote sensing and for climate modeling. We describe the design of a space-borne polarimeter that was derived from the key science requirements. The performance of this candidate polarimeter, operating in the UV/VIS/NIR spectral regions, is described. The optical design form and various optical performance parameters, including transmittance calculations of the polarimeter’s spectral channels showing the “leakage” of polarization states, as well as the degree of polarization as function of wavelength and field of view are presented for the various wavelength regions. An overview of the instrument performance and driving operational parameters is presented.

Calcium fluoride is a desirable material for optical design of space systems in the ultraviolet, visible, and infrared bands. Modern calcium fluoride materials fabricated for the photolithography industry are highly resistant to space radiation. The wide wavelength band and low dispersion are also desirable properties. Unfortunately, calcium fluoride has a host of significant material property issues which hinder its use in the space environment. Low hardness, susceptibility to thermal and mechanical shock, and large coefficient of thermal expansion present significant challenges during development of opto-mechanical designs. Sandia National Laboratories Monitoring Systems and Technology Center has fielded a calcium fluoride based optical system for use in space. The Sandia design solution is based upon a spring-loaded mount which uses no volatile organic compounds. The theory of the Sandia solution is developed and design rules are presented. The Sandia design solution is illustrated for a specific example. Example design and margin calculations are shown. Finally, lessons learned from our design realization and qualification testing efforts are shared for the benefit of the community.

A novel pushbroom sensor concept is introduced which incorporates a faceted field-condensing mirror to image the same ground pixel simultaneously in several spectral bands, while eliminating temporal misregistration and MTF smear due to earth rotation. This paper presents an overview of the instrument concept and the fabrication and performance details for the mirror.

Most imaging systems today include a mosaic detector array in the focal plane. Optical designers of astronomical telescopes typically produce a design that yields a superb on-axis aerial image in the focal plane, and detector effects are included only in the analysis of the final system performance. Aplanatic optical designs (corrected for spherical aberration and coma) are widely considered to be superior to non-aplanatic designs. However, there is little merit in an aplanatic design for wide field applications because one needs to optimize some-field-weighted average measure of resolution over the desired operational field of-view (OFOV). Furthermore, when used with a mosaic detector array in the focal plane, detector effects eliminate the advantage of the aplanatic design even at small field angles. For wide fields of view, the focal plane is frequently despaced to balance field curvature with defocus thus obtaining better overall performance. We will demonstrate that including detector effects in the design process results in a different optimal (non-aplanatic) design for each OFOV that is even superior to an optimally despaced aplanatic design.

The meniscus between two immiscible liquids can be used as an optical lens. A change in curvature of this meniscus by electrowetting leads to a change in focal distance. We demonstrate that two liquids in a tube form a self-centered tunable lens of high optical quality. Several properties were studied, such as optical performance, electrical characteristics and dynamic behavior. We designed and constructed a miniature camera module based on this tunable lens and show that it is very well suited for use in portable applications.

A compact scanning deflectometer is presented for the fast topography measurement of semiconductor wafers. The technique, however, is equally well suited for any flat or slightly curved specular reflective surface. The measurement principle is based on the 2D measurement of the local slope vector by means of a narrow Laser beam scanning rapidly across the sample surface. The fast linear scanning is combined with sample rotation to measure the complete surface of circular samples. There is no physical contact to the measured surface. The topography of the sample is derived from the slope data by a novel 2D integration method, which is robust with respect to noise in the slope signals. We present the full-size topography of unpatterned and patterned wafers of different polishing quality.

The majority of the beam splitters for three beam tracking in commercial DVD pickup employ lamellar phase gratings, which already provides sufficient efficiency. However, for a pickup with all diffractive elements, the power budget becomes more critical, and a higher efficiency of the beam splitter is required. In this paper, we have investigated and will present the influence of the desired energy ratio between the zeroth order central beam to the first order side beam on the total efficiency of the beam splitter. The simulation based on scalar diffraction theory shows that the total efficiency of a lamellar phase grating will drop as the ratio decrease, which can be improved by employing a more sophisticated surface relief. The equal-side triangular profile has been investigated as a solution and the geometrical size of the profile has been optimized for several desired energy ratio. For a low cost fabrication process with photolithography, the total efficiency loss due to quantization with different quantization levels of the triangular surface relief has been estimated with scalar diffraction theory. This paper is concluded with a table of optimal phase level for a given energy ratio and desired minimum total efficiency with the consideration of fabrication cost.

The sensitivity of an image position grid to local heat applied to the TIR surface of a prism in a Wynne Dyson design was examined. The mechanisms resulting in the shape and magnitude of the shape change are explored qualitatively and with FEA analysis. The FEA package was used to generate temperature and deformation results, which were then ported to a ray trace program and the impact on the image grid was determined. A device was made to check the validity of the models. The heat load was applied by inserting thermocouple instrumented Watlow cartridge heaters in an aluminum block, placing the aluminum block 127 microns from the TIR surface, and heating an 8mm square surface area of the block to 1.3C, 2.5C and 5.0C. These heat loads resulted in peak image errors of 68nm/C with vector error maps in an annular pattern roughly centered on the geometrical center of the heat load. The models developed were useful for qualitative predictions of the performance, but need tuning to increase the accuracy. Although linear superposition cannot be used to calculate the effect of combined local heat sources, due to the non-linear behavior of the thermal effects, the results can be used to estimate the maximum stray local heat that can be tolerated on this optical surface.

The tunable near InfraRed Lyot filter (TNIRLF) is one of the focal plane instruments for Advanced Technology Solar Telescope (ATST) project of the National Solar Observatory (NSO). Achromatic half waveplate and quarter waveplates working from 1000 nm to 1700 nm will be used in this filter. In this paper, we give a description of the design and development for the synthesized achromatic waveplates using quartz plates. The retardance variation is within 1% over the full spectral range and we discuss the variance of optical axis.

The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. As a core NIF early light diagnostic, this system measures shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. A 659.5 nm VISAR probe laser illuminates the target. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 33-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two VISAR (Velocity Interferometer System for Any Reflector) interferometers. Both streak cameras and CCD cameras record the images. Total track is 75 feet. The front end of the optical relay can be temporarily removed from the equatorial port, allowing for other experimenters to use that port. The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. Along with special coatings on the mirrors, cutoff filters reject the NIF drive laser wavelengths and pass a band of wavelengths for VISAR, for passive shock breakout light, or for thermal imaging light (bypassing the interferometers). Finite Element Analysis was performed on all mounting structures. All optical lenses are on kinematic mounts, so that the pointing accuracy of the optical axis can be checked. A two-color laser alignment scheme is discussed.

The optical interconnection between fibers and optical waveguides has been the most important factor for low-cost packaging of multi-channel PLC-type optical devices. Recently, polymer based PLC-type optical devices have been considered as an alternative fabrication method and are particularly attractive because of their satisfactory light guiding characteristics and easy fabrication process. In this study, a novel micro-mechanical passive alignment method for multi-channel polymer PLC devices has been designed and fabricated using a hot embossing technique. The main design issue is simultaneous fabrication of micro channels for single-mode waveguides and micro-pedestals for passive alignment on a polymer PLC surface in one step by hot embossing. Since the hot embossing process uses wet-etched silicon mould for pedestals, and alignment pits on silicon optical bench (SiOB) are also wet-etched in KOH solution, optical alignment was achieved through the simple insertion of micro pedestals into the alignment pits on SiOB. The hot embossed waveguide and passive alignment pedestals have been shown an accuracy of ± 0.5 μm. The propagation loss of fabricated single-mode polymer PLC was 0.83 dB/cm at a wavelength of 1550 nm, and passively aligned polymer PLC device with an accurate SiOB showed an average 0.67 dB coupling loss.

A new way to evaluate the diffraction efficiency of the diffractive optical element (DOE), which serves as an aberration corrector in an infrared hybrid optical system, is proposed. The directly measured ensquared energy of the hybrid optical system is obtained through an experimental test. Then, the actual line spread function (LSF) of the system under test is measured, and the point spread function (PSF) is calculated from LSF based on the symmetric property of the system. The PSF is used to calculate the so-called derived ensquared energy. The ratio of the directly measured and the derived ensquared energy, defined as the diffraction efficiency of the DOE, represents the fraction of the energy focused onto the image point over the total input energy on the image plane, because the energy loss is caused by the scattering from the DOE corrector. The hybrid optical system, experimental setup, evaluation procedure, and the final results will be presented.

The merit function landscape of systems of thin lenses in contact, which are perhaps the simplest possible types of optical systems, shows remarkable regularities. It is easier to understand how the optimization parameter space of these simple systems is divided into basins of attraction for the various local minima if one focuses on the (Morse index 1) saddle points in the landscape rather than on the local minima themselves. The existence and the basic properties of these saddle points can be predicted by thin-lens theory, which is applied on a simplified model of the merit function containing only third-order spherical aberration. The predictions of this simplified model are confirmed by numerical results obtained with a typical merit function based on ray tracing.

When Extreme Ultraviolet mirror systems having several high-order aspheric surfaces are optimized, the configurations often enter into highly unstable regions of the parameter space. Small changes of system parameters lead then to large changes in ray paths, and therefore optimization algorithms crash because certain assumptions upon which they are based become invalid. We describe a technique that keeps the configuration away from the unstable regions. The central component of our technique is a finite-aberration quantity, the so-called quasi-invariant, which has been originally introduced by H. A. Buchdahl. The quasi-invariant is computed for several rays in the system, and its average change per surface is determined for all surfaces. Small values of these average changes indicate stability. The stabilization technique consists of two steps: First, we obtain a stable initial configuration for subsequent optimization by choosing the system parameters such that the quasi-invariant change per surface is minimal. Then, if the average changes per surfaces of the quasi-invariant remain small during optimization, the configuration is kept in the safe region of the parameter space. This technique is applicable for arbitrary rotationally symmetric optical systems. Examples from the design of aspheric mirror systems for EUV lithography will be given.

Many practical approaches have been developed for computing the point spread function (PSF) of imaging systems and the subject has been extensively studied for many years, since this has been a classical topic in optics. In recent times, the exact numerical calculation of the diffraction integrals and, hence, of the PSF of image forming systems has been successfully addressed. These methods are based on the determination of the critical points and the semi-periodic zones of the integrand on the plane of the aperture, followed by the summation for each of the zones. In the present work we address a comparison between an approximate calculation method based on the classical approach and the cited exact numerical procedures, mainly regarding the required computational effort involved.

We develop a method for the calculation of the integrals arising in the diffraction theory of aberrations. This method is developed from in a previous one based in the division of the diffracting aperture in semiperiodic zones, which enabled the exact calculation of the Point-Spread Function of an optical system. By a careful analysis of the integration process and of the properties of the semiperiodic zones, we develop a set of formulae that give an approximate value of the result of the diffraction integrals. This permits to avoid the numerical calculation of the integrals, which is a computationally intensive procedure and enables a substantial reduction of the computation times. The method has been tested on aberration-free optical systems and real optical systems and has shown a good accuracy, although some minor problems require further investigation.

The use of wavefront measurements to deduce the state of multiple optics in a telescope beam train - their misalignments and figure errors - can be confused by the fact that there are multiple potential sources for the same measured error. This talk applies Kalman filtering techniques as a tool for separating true telescope errors from artifactual testing errors in the alignment and testing of NASA's James Webb Space Telescope, a large segmented-aperture cryogenic telescope to be launched after 2010.

Since end of 2003 the TII-3D - the new contact topography measuring device for measuring aspherical and spherical surfaces - is available on market. Due to its novel technology, the system is specified to measure a large range with λ/10 accuracy, therefore being a very flexible tool for pre- and post-measurements in high quality zonal polishing processes like MRF. At the University of Applied Sciences Deggendorf a testing series has been carries out to compare the results of the TII-3D with CGH-interferometric measurements on aspherical surfaces. An analysis of the measurement errors is shown and ranking of the different metrology systems for production processes of high quality aspherical lenses is given.

We present a method for measuring an optical system’s effective focal length with a single mode fiber array and a wedge prism. Light emitted by the input fiber near the focal plane is collimated, reflected back in two angularly separated beams, and detected by the output fibers in the auto-collimation configuration. Measurement precision of a micron can be achieved due to the precision of fiber spacing and the position sensitivity of single-mode coupling. Absolute accuracy depends on factors such as optical design configuration, metrology, aberrations, and environmental control, and can be better than 10 micron. By varying input wavelength and field angle, this technique can be utilized to precisely characterize chromatic dispersion and distortion of the optics. Furthermore, because the technique only requires compact opto-mechanical accessories and electronic apparatus, it can be readily carried out on large optical systems in the field.

The lens is one of the most commonly used optical elements. Yet it is sometimes difficult to make accurate effective focal length and pupil position measurements, especially for long focal length lenses. Many measurement methods rely on a mechanical measurement to determine the back focal length, or may require careful operator discrimination in determining the best focus position. Aberrations may confuse an automatic focal length measurement system. However, an accurate determination of the optical properties of a lens is often critical for building an accurate system model. We have developed a method for measurement of the focal length, pupil plane and collimation positions of positive lenses using a Shack-Hartmann wavefront sensor. The SHWFS uses a micro-optic lens array to separate the incoming wavefront into a pattern of focal spots. The position of these focal spots is related to the local wavefront slope. Wavefront reconstruction allows the complete incident wavefront to be retrieved. A Zernike decomposition reconstructor is used to separate the effects of lens focal power from other aberrations. The lens under test is illuminated by a point source on a computer-controlled stage. The transmitted wavefront was recorded by the SHWFS while the source was translated over a few mm range. By analyzing the Zernike coefficient associated with defocus, we were able to extract the focal length, pupil plane and collimation positions using a least squares fitting procedure. This procedure was tested for a variety of lenses of varying focal lengths, from 10 to 1000 mm focal length, and showed excellent repeatability and accuracy. These measurements were compared to knife-edge, manufacturer’s specification, and ray-tracing analysis for verification testing.

A simple technique for focal length measurements of adaptive micro-lenses using z-scan is reported. Focal length is one of the most important parameters of any lens. The effective focal length is measured with reference to the principal points that are not easy to find especially for micro-lenses. In addition, variable focal length microlenses pose a different challenge that makes the process of determining their exact focal length a tedious and difficult process. Classical methods such as nodal slide and magnification have been used for focal length determination. Also, advanced Interference techniques such as Talbot, Moire, Digital Speckle, Zygo and Joint Fourier Transform were used for focal length measurements. These techniques require more elaborate setups and difficult to implement, especially for microlenses. Recently a power meter was used to find the focal length of an unknown lens. Most of the techniques mentioned above proof to be not simple for microlens characterization. The z-scan technique has been implemented, for quite sometimes, to characterize the third-order effects of a nonlinear optical material. The z-scan provides information on both the sign and magnitude of the non-linear refractive index and offer advantage of simplicity. We have used a regular lens to collimate and focus light unto the lens under test. By scanning the lens under test and measuring the on-axis intensity, one can find the focal length. This is because the on-axis intensity is proportional to the phase of the lens and therefore the focal length. In the case of an adaptive lens with its focal length is a function of the applied voltage, the scanning occurs for each voltage value that will correspond to the on-axis refractive index change and therefore the far field on-axis intensity. This described technique above is easy to implement and can achieve good accuracy due to the inherent sensitivity of the z-scan.

Every few years new polishing technologies attempt to make the transition from the research laboratory into the commercial sector. Success awaits any process that is well controlled and predictable (e.g., deterministic), rapid, capable of smoothing to sub-nm rms roughness levels while removing damage from grinding, affordable, and easily implemented. Applicability to different optical materials and a variety of part sizes and shapes is extremely important, but may not be required for a new technology to succeed in a niche market. This paper reviews six innovations in polishing of precision optics: Canon’s Super-Smooth Polisher (CSSP) that uses a sub-aperture pitch lap - a relatively mature but important base-line technology; Nikon / Osaka University’s RF Plasma Chemical Vaporization Machining (CVM); Epion’s Gas Cluster Ion Beam (GCIB) Process; the IOM University of Leipzig / NTGL Ion Beam Finishing (IBF) Technology; Zeeko’s “Precessions” Process with a sub-aperture section of an inflatable pad; and QED Technology’s Magnetorheological Finishing (MRF) with a magnetic fluid ribbon. The removal mechanism and some recent achievements for each process are discussed.

The lifetime of standard magnetorheological (MR) polishing fluids, used for example in polishing machines for optical applications, is limited. Scanning electron microscope examinations as well as chemical analyses of the fluid had been undertaken in order to investigate reasons for limited lifetime. We found out that the removal rate decreases during the course of time. However, the usable fluid life is most limited by the point of time when the critical minimum amount of fluid, necessary to ensure circulation, is reached. The results in association with a new fluid conditioner show, that a standard MR polishing fluid may be used for longer periods than common periods of about 2 weeks.

Since the 2003 Annual Meeting, the Precessions process has become accepted as an efficient method for polishing and figuring moderate-sized axially-symmetric aspheric parts in industry. In this paper, we report on some very significant new advances beyond this capability. The first is the demonstration of the process on substantially larger diameter parts than worked hitherto - in particular, a precision-ground 500mm diameter deeply-concave aspheric mirror. We describe the consequences of polishing large parts with the axis of the part vertical, in contrast to the horizontal axis of the smaller machines. Issues include slurry puddling and settlement in concave forms, process-uniformity, adequate support of the part and handling. We then report on recent work developing the Precessions process for non axially-symmetric surfaces including free-form. The correct relationship of the process with metrology has proved to be complex on several fronts, one example being differing descriptions of form either along a surface or its projection. We present our experience using profilometry and interferometry on precision-ground and polished surfaces, and in achieving absolute form with known base radius. Finally, we remark on the potential power of a priori predictions of achievable surface quality when optimizing optical system designs.

The demand for high performance lightweight mirrors has never been greater. The coming years will require lighter and higher performance mirrors and in greater numbers than is currently available. Applications include both ground and space based telescopes, surveillance, navigation, guidance, and tracking and control systems. For instance, the total requirement for US government sponsored systems alone is projected to be greater than 200 m²/year¹. Given that the total current global production capacity is on the order of 50 m²/year¹, the need and opportunity to rapidly produce high quality optics is readily apparent. Key areas of concern for all these programs are not only the mission critical optical performance metrics, but also the ability to meet the timeline for deployment. As such, any potential reduction in the long lead times for manufactured optical systems and components is critical. The associated improvements with such advancements would lead to reductions in schedule and acquisition cost, as well as increased performance. Trex’s patented CVC SiC process is capable of rapidly producing high performance SiC optics for any optical system. This paper will summarize the CVC SiC production process and the current optical performance levels, as well as future areas of work.

The importance of micro-optical elements for the development of hi-tech products is now clear. However there is a wide range of fabrication techniques used to produce these optical components, each having advantages and disadvantages. It is vital therefore that this range of fabrication techniques are examined and compared. One of the most promising fabrication techniques, the photoresist reflow method, will be discussed in detail. Particular emphasis shall be given to the case where the lens profiles differ from that predicted by the current energy minimization models. This case is of interest as it allows the production of aspheric lenses which have a wide range of applications including, beam shaping, power transfer and fiber coupling. The fabrication of these aspheric lenses using the photoresist reflow method currently requires an iterative experimental process as there is currently no model that accurately predicts the lens profiles from first principles. In this paper we examine a proposed model that is based on first principles, the Curvature Correction Model, CCM, and attempt to verify its applicability to the photoresist reflow method. In this paper we examine a current methods used to solve the CCM and discuss the predicted lens profiles. The resulting lens profiles allow us to predict initial fabrication parameters to enable us to design specific lens profiles. Further examination of a number of polynomial models that have been presented in the literature is also carried out.

This paper presents a purely mechanical means of producing highly concentric spherical lenses at the endfaces of optical fibers. The production process has two stages. First conical lenses are produced in a grinding process that ensures excellent concentricity. Then the conical lenses are transformed to spherical lenses using a novel process called loose abrasive blasting. The cone grinding is carried out on a micro-grinding machine that has a sophisticated control system that enables the production of precision conical lenses. The blasting is carried out on a diamond blasting machine. Plots showing automatic centering performance of the micro-grinding machine and scanning electron microscopy photographs of the conical and spherical lenses are presented.

The paper presents a new processing method for design and fabrication of microlens by microfluidic deposition, in which the lenses can be formed on the media with high precise location in the fabrication process. First we may apply physical vaporization deposition (PVD) or spin coating to fabricate a thin film; secondly, the hydrophilic pattern specified by the mask of lenses can be created by photolithography, where the special lens media is made herein. Finally, the liquid solution of lens material is deposited onto the predetermined location of the lens media by the drop-on-demand fluidic actuator; thus, the microlenses are consequently formed after the complete evaporation of solvent in the solution.

The development of an inexpensive, reproducible and highly accurate method for the production of microlens arrays is of vital importance to the next generation of optics based technologies. One technique that has been used to produce arrays is the inkjet deposition method. When lenses are produced using this method they are normally found to have spherical profiles. Although spherical lenses are of great importance in optics we note that aspheric lenses also have a wide number of applications. These include beam shaping, power transfer and fiber coupling. To date attempts to produce aspheric lenses using the inkjet method have failed. In this report we propose a novel method to produce aspheric lenses by applying an external electric field to the lens while the lens is in liquid form. In this report we describe initial experiments involving both single lenses that prove the initial concept and also initial studies of arrays of lenses produced using inkjet technique. The single lenses are shown to differ substantially from the standard case (no E-field) post curing.

Driven by the fast development in optical fiber interconnections, there exists an increasingly growing demand for wider bandwidth. DWDM technology can extremely enhance the number of wavelengths (de)multiplexed. Among many DWDM devices, free-space diffraction gratings (FSDG) play an important role, with the advantages of parallel and athermal processing as well as low polarization-dependent losses. In our work, we describe by means of the rigorous coupled-wave analysis (RCWA) that high-density holographic photoresist gratings, if being in optimized profile parameters, can realize high diffraction efficiencies, e.g., the first Bragg diffraction efficiency can theoretically achieve more than 90% both in TE and TM polarizations. And we have successfully fabricated the 600 lines/mm photoresist gratings whose first Bragg diffraction efficiency can experimentally reach 80% with the grating depth 2.9μm. The experiment process is presented in detail, and the experimental result is in good agreement with the theoretical one.

A practical optical printed circuit board (PCB) was demonstrated, using a waveguide-embedded optical backplane and processing boards. The polymeric waveguide was produced by means of a hot embossing technique then embedded following a conventional lamination processes. The core size of waveguide was 100 x 60 μm² (input section), 60 x 60 μm² (output section), and the propagation loss of tapered polymeric waveguide was approximately 0.1 dB/cm at 850 nm. We prepared a optical backplane with polymeric waveguide by using conventional multilayer board lamination processes. The transmission power and dimension of the optical backplane was same as those of waveguide before lamination. A metal optical bench was used as a packaging die for the optical devices and the integrated circuit chips in both the transmitter and the receiver processing boards. We used a 1×4 850 nm VCSEL array with 2 dBm of output power for the transmitter and a PIN photodiode array for the receiver. We successfully demonstrated 8 Gb/s of data transmission between the transmitter processing board and the optical backplane board.

The multi-configurative microscopic system for inspecting the wire-bonding of reed frame is designed. Object rays is nearly collimated by a objective lens group which is a common lens group of x2 and x6 imaging lens systems and is splitted by two beam-splitters composed of a penta-prism and a refracting prism. And object rays started from the central region and the boundary region(reed frame region) on semiconductor chip(that is, the object) are imaged at the two different imaging planes by x2 and x6 imaging lens groups, respectively. The x6 imaging lens system with a constant object distance and a constant magnification is well designed by general imaging optics system design method. However, since the depth of wire structure on the reed frame has about ±3 mm, in order to observe by a constant magnification and at a fixed imaging plane without the dependency on the variation of objective distance generated by the depth of wire structure on the reed frame, the imaging lens system is composed of two separated groups, which should be moved along nonlinear locus like mechanically compensated zoom lenses. The nonlinear equations for zoom locus are derived by using the Gaussian bracket. Refraction powers and positions of each groups are numerically determined by solving the equations, and initial design data for each groups is obtained by using Seidel third order aberration theory. The optimization technique is finally utilized to obtain this multi-configurative microscopic system.

A fast (F/1.55) and wide-angle refractive camera objective has been developed to work with a large-size CCD on the focal plane of the spectrograph of Mont Megantique telescope for large spectral coverage from UV to VIS and up to NIR. The novel camera objective has been designed and optimized with three different glass combinations in order to have higher throughputs for large spectral coverage, especially in UV region. The tolerance analysis of the camera objective is given in the paper. The final opto-mechanical design of the objective is discussed with the consideration of the manufacturing tolerance in the optical and mechanical parts, as given in this paper. The used components have been minimized to reduce the light inherent lost. The optical testing results displayed the good optical performance of the camera with the required resolution for the whole FOV, as predicted by the optical simulation and computation. The broadband AR coating, enhanced on UV region, have been used on each surface of the lenses in the optical system.

The control systems of the miniature robots are suggested for their motion over internal surfaces inside of the small diameter tubes. The mechanical system, information-measuring sensor and control systems are considered. Three versions of the mechanical systems are suggested: electromagnetic, triad wheels and conversion of rotation motion to translation one. The electromagnetic mechanism use push pull tipe method for translation motion realization. Developed schemes in the modules design of control systems were checked experimentally on the robot’s prototypes. Some of the results of the computer simulation illustrate the multilink robot control motion along the internal diameters of the tubes. This work was fulfilled under financial support of the Russian Found of Fundamental researches N 01-01-00913 and in frames of Federal Multi Purpose Scientific and Technical Program of Ministry of Industry, Science and Technologies: “Researches and Developments on priority directions of science and technology”, “Knowledgeable basic investigations” block, “Basic investigations at the field of physics sciences” part Mechanics.