This PDF file contains the front matter associated with SPIE Proceedings Volume 7657, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

A novel ultra-precision positioning technique based on phase tracking and locking is presented, which extremely simplifies the structure of the ultra-precision positioning system by taking the phase difference between the measuring signal and reference signal of dual-frequency laser interferometer instead of monitoring displacement data from interferometer as the control signal of micro-displacement actuator. In order to real-time compensate static positioning errors of the system due to factors such as hysteresis and creeping of the working platform, the phase discrimination unit must meet requirements on high frequency response and high precision. To avoid the shortcomings such as low phase discrimination accuracy and narrow measuring bandwidth of the conventional analog and digital phase difference detecting methods, an integrated circuit used in communications for phase difference detecting, AD8302, is introduced into the ultra-precision measuring and control circuit, and a high precision phase discrimination circuit with a measuring bandwidth covering 20kHz to 80MHz is developed after thorough study of the principles of XOR-type phase discrimination, and phase shifting method is used to solve the polarity problem brought by direction discrimination. Experiment results show that the accuracy of phase discrimination is better than 0.1° within the phase difference range of -180° to +180° at the center frequency 20MHz, and the corresponding displacement resolution of the positioning platform is 0.05nm. This technique can also be applied to the phase discrimination units of other instruments and equipments.

We present a miniature Fabry-Perot pressure sensor which is made of silica glass capillary tubing and two single mode fibers. The sensor has an inside diameter of 125 μm and outside diameter of 240 μm, and its sensitivity can be adjusted by controlling the sensor gauge length. The sensor has been tested for static pressure response, showing a sensitivity of 3.98 pm/kPa, a resolution of 0.1kPa, a linearity of 99.76% and a hysteresis of 0.12%, and capability of operation at temperatures up to 500°C. This sensor is immune to electromagnetic interference and has high-temperature capability, may be used in applications where high temperature and/or small size are important.

Silicon based racetrack resonator are demonstrated as highly sensitive acceleration sensor. The sensor consists of a straight waveguide coupled with a racetrack resonator, and a crossbeam seismic mass serving as the vibration unit. The resonant wavelength, which depends on the optical phase change per round trip, is sensitive to external accelerations due to the waveguide increment and stress-optic effect. With a 30-dB signal-to-noise ratio measurement system, the detection limit and dynamic range are theoretically obtained as high as 4.8×10^-4 g under the frequency of acceleration below 200 Hz. The new silicon-based accelerometer will have great potential in seismic prospecting due to its high sensitivity, light weight and immunity to electromagnetic interference.

We present the fabrication and characterization of mid-infrared photonic-crystal quantum cascade lasers (PC QCLs). Holographic lithography (HL) instead of electron beam lithography (EBL) has been used in the preparation of PC lattices to simplify the fabrication procedures. Compared with the EBL, the HL technique provides a rapid and large area processing capability with high efficiency and low cost. Two PC lattice structures, namely a first-order square lattice and a tilted rectangular lattice were defined using a multi-exposure two-beam holographic technique, respectively. The devices with square PC lattice exhibit single longitudinal mode emission with a side mode suppression ratio (SMSR) about 20 dB. While, no sign of improvement in the far field distribution for the device was observed, which was attributed to the lack of two-dimensional coupling mechanism in this lattice structure. Whereas devices with tilted rectangular lattice PC lattices exhibit the near-diffraction-limited beam emission with the full width at half maximum of the far field divergence angles about 4.5° for devices with stripe widths of 55 μm. Single longitudinal mode emission with SMSR≈20 dB was achieved in the temperature range of 80-210 K. The single-facet output power was above 510 mW for a 55 μm × 2.5 mm laser bar at 85 K in pulsed operation. This economical and efficient holographic fabrication process of photonic crystal quantum cascade lasers with high power, single-mode operation and near-diffraction-limited beam quality would pave the way for the wide commercial application of the devices.

Nano-devices are increasingly required, the fabrication cost of nano-devices is quite high due to high resolution requirement. Nanoimprint lithography(NIL) is a promising technology for nano devices fabrication due to its low cost and high resolution. However, it still suffers from the large area uniformity and imprint defects problems. Herein, temperature-pressure variation soft press process are used in Simultaneous Thermal and UV (STU) imprint to enhance the uniformity and quality of pattern. This method is used to pattern high quality photonic crystals and gratings.

Detailed analysis was carried out upon the modal wavefront sensor (MWFS) employed multiple holographic optical elements(MHOEs). The distribution of diffraction field on the detector plane of the MWFS was present, and further deduction was made to gain an analytical expression of intensity distribution of the diffraction field, which resulted in the unification with the theory of mode-biased wavefront sensor. For sake of simplicity in numerical simulation of the MWFS, we have done some modification to the original approach. An equivalent model of the MWFS has been proposed, in which we choose two tilt conjugate plane waves to replace the tilt convergent spherical waves as the reference waves in recording holograms, and place a convergent lens in close proximity to the rear surface of holographic element. We validated the principle of the MWFS by numerical simulations employed the equivalent model. The simulation results were consistent with the theoretical ones.

The main advantageous features of laser interference lithography (LIL) technology in fabrication of nano structures and devices are high resolution, low cost and high efficiency. By using LIL, the graded-index patterns consist of periodic modified lines (MLs) on the periodic square patterns. Patterns with MLs formed on SiO₂ deposited on GaAs substrate. The orientation and periodicity of MLs are shown to depend on the configuration of the incident laser beams. Periodic arrays of holes in GaAs, covered with SiO₂ bubbles, were directly written into the sample within only some minutes. The diameters of the smallest holes were less than 30 nm. The smallest modification features of the GaAs were less than 5 nm. Four-beam LIL was shown to be a good technology to generate graded-index photonic crystals with square lattice. High intensity enhancement and sub-wavelength focusing were achieved simultaneously. The results indicate a new lowcost and high-efficiency way of fabricating planar lens.

Cutting heat is one of the important physical subjects in the cutting process. Cutting heat together with cutting temperature produced by the cutting process will directly have effects on the tool wear and the life as well as on the workpiece processing precision and surface quality. The feature size of the workpiece is usually several microns. Thus, the tiny changes of cutting temperature will affect the workpiece on the surface quality and accuracy. Therefore, cutting heat and temperature generated in micro-milling will have significantly different effect than the one in the traditional tools cutting. In this paper, a two-dimensional coupled thermal-mechanical finite element model is adopted to determine thermal fields and cutting temperature during the Micro-milling process, by using software Deform-2D. The effect of tool edge radius on effective stress, effective strain, velocity field and cutting temperature distribution in micro-milling of aluminum alloy Al2024-T6 were investigated and analyzed. Also, the transient cutting temperature distribution was simulated dynamically. The simulation results show that the cutting temperature in Micro-milling is lower than those occurring in conventional milling processes due to the small loads and low cutting velocity. With increase of tool edge radius, the maximum temperature region gradually occurs on the contact region between finished surfaced and flank face of micro-cutter, instead of the rake face or the corner of micro-cutter. And this phenomenon shows an obvious size effect.

In semiconductor industry, exposure tools have been improved in resolution. 193 nm lithography is one of the promising technologies for the fabrication of critical dimension from 100 to 32 nm. The optical performance of projection lens is the key factor to realize high resolution pattern. This paper presents the design process of a refractive lithography projection lens utilizing aspheric surfaces. The objective, as built, has a numerical aperture of 0.75, a maximum astigmatism of 30 nm and a total focal plane deviation of 45 nm. With the assistant of resolution enhancement technology, image resolution can reach 90 nm. Aspheric surfaces can be used to correct aberrations, to make optical systems more compact, and in some cases to reduce cost. Systems with and without aspheric surfaces are compared in the paper so as to find their differences in aberrations and configuration. We found that aspheric surfaces dramatically decrease the RMS wavefront error from 3 nm to 1 nm. Differ in position of aspheres can be used to correct aperture dependent aberrations (spherical aberration), and to correct field dependent aberrations (distortion and field curvature). We explored the connection between position of aspheres and different aberrations by APS (Aspheric surfaces selecting factor). Aspheric surfaces also make the system more applicable by reducing the system volume and leaving proper edge thickness for mechanical structure.

Metal nanostrip array for light transmission enhancement in the nanoslit is studied using a finite-difference time-domain method (FDTD). The strips with uniform shape are placed on upper side of a metal film with the nanoslit fabricated in it. It is found that the transmission efficiency can be promoted with an optimization of the strip. Effects of the single strip on the promotion are discussed in detail, a Fabry-Perot resonance model is competent for well understanding the phenomena.

Optical properties of bowtie antennas are investigated using a numerical method of finite-difference time-domain (FDTD). The optical response in the antenna feed gap is simulated as functions of its geometry parameters (flare angle, arm length, apex width, thickness, gap dimension, as well as the index of substrate), which provide a clear guideline to exploit such antenna structures in practice.

The 3D finite difference time domain (FDTD) method was employed to simulate the polarization characteristic of the tapered metal-coated optical fiber probe in the near-field optical. The Scanning Near-field Optic Microscopy (SNOM)'s applications would be extended by controlling the exit light's polarization of the optical fiber probe and analyzing the polarized light which passes through the sample. Uniaxial Perfectly Matched Layers (UPMLs) are used for the Absorbing Boundary Condition, and the Drude model is used to deal with the non-magnetic metal. The light intensity distribution near the optical fiber tip was calculated with linear-polarized incident light. A general relationship between the extinction ration and the probe varying with its relevant parameters has been found by means of making alternations on the aperture diameter(40nm-120nm), the cone angle(20°-90°), the thickness of metal film(50nm-150nm) and material(silver, aluminum) as well as the incident light wavelength(350nm-1000nm) and other parameters. The results show that the above multi parameters have produced a co-effect on the polarization characteristics of the optical fiber probe. Once the other parameters remain constant, the extinction ratio is increasing as the aperture diameter or metal film thickness increases. And the extinction ratio could be decreasing, increasing or fluctuant as the cone angle increases in the different conditions. Al's extinction ration usually is better than Ag's under the same conditions. The wavelength's impact should be linked to the metal's complex permittivity. Therefore, the results have positive significance to the design and application of the high extinction ratio fiber probe.

Microlens has a wide application in the micro-optical systems. In this paper, wet etching process is adopted to fabricate high-definition (HD) diffractive objective lens. During the design process, Rayleigh-Sommerfeld integral transformation is used to optimize the traditional G-S algorithm, so that the simulation algorithm is more precise and the diffraction efficiency of objective lens is improved remarkably . In the manufacture process, which is based on the anisotropic etching characteristic of silicon materials, the fabrication method introduced in this paper is different with other traditional fabrication approaches of micro-optical device, in which the accurate and complex multi-step photolithography is not needed, instead, a single-step photolithography and a dual-step wet etching process is adopted. In the first step of the wet etching, an inverted pyramid structure was formed on the surface of silicon wafer, depending on the difference of corrosion features between Si-100 plane and Si-111 plane, and the principle of automatic stop. In the second step, surface relief stair-structure with different height is obtained by keeping corroding according to the erotion features between Si-111 plane and Si-114 plane. The surface morphology and optical tests of the lens indicate that the full outline of its stair-structure is clear, the surface roughness in the range of tens of nanometer, which meets the requirements of optical mirror.

This study proposes a thinned-cladding zeolite coated long period fiber grating (LPFG) chemical sensor. The cladding outside the grating zone is etched by hydrofluoric (HF) acid, and then the zeolite film is coated on the thinned grating. The sensitivity characteristics of the LPFG to different external refractive indices are investigated. By etching cladding, the resonant wavelength shifts towards the longer wavelength (red shift) while the attenuation band depth is increased. In addition, with very large surface-to-mass ratio, zeolitic pores can efficiently adsorb molecules from the ambient for highly sensitive detections. The adsorbed analyte molecules are collected and aligned in nanoscale zeolite pores. This leads to changes in the refractive index of zeolite coating, which in turn, causes resonant wavelength shift. After zeolite coating, the resonant wavelength shifts towards the shorter wavelength (blue shift) and the sensitivity to external refractive index is enhanced. The resonant wavelength of uncoated LPFG is 1563.1 nm in air and 1560.5 nm in water, with the wavelength shift of 2.6 nm, while the resonant wavelength of zeolite coated LPFG is 1543.2 nm in air. Decreases in cladding diameters and ziolite coating can effectively enhance the refractive index sensitivity of LPFG chemical sensor.

This paper describes the characteristics of a 61 element piezoelectric deformable mirror (DM) based on bulk-PZT thick film and the generation of Zernike polynomials. This device consists of a continue silicon mirror supported by 61 element piezoelectric unimorph actuators which are arranged in a hexagonal grid with spacing of 5mm. Measurements of the displacement using a laser Doppler vibrometer demonstrated that the stroke of DM was 3.8μm at 100 volt with a displacement hysteresis of approximately 9% and the operating bandwidth was greater than 10KHz. A custom phasing-shifting interferometer based on Twyman-Green interferometer was developed to measure the mirror surface shape in response to the applied voltage. The influence function of the mirror measured accorded with Gaussian function with inter-actuator coupling of approximately 5%, which was similar to the traditional piezoelectric DM with stacked actuators. To examine the ability of the mirror to replicate optical aberrations described by the Zernike polynomials, low-order Zernike modes were reproduced by calculating the voltage on each actuator using an influence function matrix. The measurement demonstrated that the deformable mirror could produce the Zernike modes up to the ninth term. Considering the low-voltage actuation as well as the capability for miniaturization of the actuator size, deformable mirror actuated by bulk-PZT thick film has a potential application for low-cost adaptive optics.

In this paper, we report the single mode operation of PC-VCSEL. The PC- VCSEL is similar to standard VCSEL except that it has photonic crystal defined by holes in the top distributed Bragg reflector. The two-dimensional photonic crystal (2-D PhC) structure is applied to lateral mode control of VCSEL. The optical confinement in VCSEL is realized by adding air-holes in the top (DBR). The holes are arranged periodically such that they form a triangular or square symmetric pattern. Light emitting aperture is formed by removing some air holes centered at photonic crystal pattern. By adjusting the photonic crystal parameters and air-holes depth, a variety of optical mode characteristic can be achieved. The characteristics of lasing lateral modes in PhC-VCSEL were analyzed by etching depth related effective index method. The contribution of PhC parameters such as lattice constant a, holes diameter d and uniform material index n to lateral mode characteristic is investigated systematically. Then two dimensional PhC was fabricated using electron beam lithography (EBL) and inductive coupled plasma reactive ion etching (ICP-RIE) on the surface of the VCSEL's top DBR. A single-fundamental- mode output power bigger than 1mW, threshold current below 5 mA, Full Width Half Maximum (FWHM) of lasing spectrum is less than 0.06 nm and over 30dB SMSR PhC-VCSEL was obtained. The lateral mode characteristics affected by different current injection was also considered.

Phase-shifted chirped fiber Bragg grating (PS-CFBG) with dual π phase shifts was studied theoretically and designed by classic transfer matrix approach. The transmission characteristics of the PS-CFBG with two transmission peaks are only directly dependent on the position of dual π phase shifts. The linewidth of two peaks increase with the chirp rate of the grating, and is not related with the wavelength difference of the peaks. A dual PS-CFBG was fabricated by ultraviolet point-by-point scanning with a ~2.4 nm/cm chirped phase mask. Phase shifts were introduced by controlling half period movement of grating accurately through the piezoelectric ceramic (PZT). The wavelength spacing, extinction ratio, and 3dB linewidth of two transmission peaks are 8nm, 20 dB and 0.08 nm, respectively, which agree with the theoretical design.

We present a method to analyze mosaic gratings' error in order to make large scale grating. The gratings' rotation condition and phase condition are designed to be controlled by the Moire fringes formed on the reference grating. The orientation and period of the Moire fringes can show the grating's rotation condition, and the phase can express the grating's phase condition. The phase congruence of the Moire fringes and the mosaic gratings is researched when the planes of reference grating and the mosaic grating's substrate are not parallel. In addition mosaic gratings' phase error brought by the drift of optical path difference is presented. And mosaic gratings' errors caused by the movement of workbench during the two exposure are analyzed. Considering all of the errors above the mosaic gratings' error is about 0.15λ. And the value is near the request of mosaic grating which is designed to be used for pulse compressor. Finally the precision of mosaic gratings' error is confirmed by the experiment. The analysis of holographic mosaic gratings' error provides the theoretical support for making large scale gratings.

Various periodic structures have been fabricated on the surface of the transparent glass by a single shot of two or three pulses. When a single shot of two pulses interfered with each other, not only did we get the ordinary grating whose period was agreed well with a theoretical estimation, but also obtained the extraordinary grating whose period was a half of that in the ordinary grating. When a single shot of three pulses interfered with each other, two-dimensional periodic microstructures distributing as a hexagonal lattice have been obtained. Different morphologies of the induced structures such as microvoids, orbicular platforms, and nanotips, could be formed with changing the pulse energy.

The theory of Gaussian beam expansion and collimation has been investigated. Based on Collins diffraction integral and matrix decomposition method, the propagation characteristics of Gaussian beam passing through beam expansion and collimation system is analyzed. The corresponding mathematical model is established. Simulations results indicate that the optical field distribution behind beam expansion and collimation system is still with Gaussian attribute. Then we demonstrate the optical field of beam with Gaussian attribute passing through 2-D sinusoidal grating. Finally, the step depth error of binary element is evaluated under illumination of Gaussian beam. The theoretical analysis and simulation results have reference for the establishment of digital lithography model and the optimization of beam expansion and collimation system.

An external laser intensity modulation system based on a micro-electromechanical systems (MEMS) mirror is presented in this paper, for application to gas sensing. The micro mirror is driven by the electrothermal actuator. The rotation direction is decided by the relative position between the driving actuator and the axis of micro-mirror. In contrast to the traditional technique of current modulation of tunable diode lasers where wavelength modulation (WM) is combined with intensity modulation (IM), the IM can be separated from WM and wavelength tuning through the external modulation furnished by the mirror reflection. The MEMS mirror with 10μm thick structure material layer and 100nm thick gold coating is formed as a circular mirror with 2mm diameter. The mirror is attached to an electrothermal actuator and is fabricated on a chip that is wire-bonded and placed on a PCB holder. There are four electrothermal actuators orthogonal to each other that are connected to the circular mirror. Double-loop serpentine springs are used to attach the four actuators to the micro mirror. Each three-beam actuator is attached to a spring at one end that connects the actuator to the mirror and fixed to the substrate at the other end. The actuators are of two different types regarding length: 1.8 mm from hereon called the long actuator and 1.35 mm called the short actuator. Characterizing the frequency response and measuring the modulation performance of the MEMS mirror is presented in this work. Intensity modulation depth from very low values to about 100 percent can be achieved through adjusting the MEMS mirror's reflection position and driving voltage. The intensity-modulated laser source is used for photoacoustic gas sensing in order to recover the target gas absorption line profile based on tunable diode laser spectroscopy. The target gas is 1 percent acetylene balanced by nitrogen and the target absorption line is P17 of acetylene at 1535.39nm. Good agreement between experimental results and theoretical simulations is obtained.

Space-borne Imaging Fourier Transform Spectrometer, which selects plane mirrors as its movable mirror and fixed mirrors, adopts dynamic adjustment system (DAS) to keep the alignment of the two mirrors. This paper addresses a DAS scheme in the space-borne FTS.

Vertical-Cavity Surface-Emitting Lasers (VCSEL) of single mode have the potential advantage in the domains of optical information network, routing interactions, optical information storage and data transmission for their excellent performance. However, operating on the single-mode model in the whole pumped area is not solved, which impacts the technologies and applications. In this paper, a new research on VCSEL of single mode multilayer photonic crystal is presented. In the structure of photonic crystal, defects in the horizontal direction are provided by the micro-cavity, while the AIR-KTP interface on the top and the KTP-DBR (Distributed Bragg Reflection) interface at the bottom of cavity provide the defects in the vertical direction, which form quantum defects of electron-hole pairs. The PC-VCSEL in the paper has excellent mode-selection characteristics, which can operate continuously at 850nm in single mode. The single-mode suppression ratio (SMSR) of 45dB is obtained in a wide dynamic range. The PC-VCSEL is expected to become a high-power single-mode light in the future.

As the critical dimension of chip shrinking the semiconductor industry has developed fully from deep sub-micron to the nano-dimension. In particular, entering the nano-dimension, lithography mask technology, among a variety of lithography method, has become a key technology which can be applied to determine their prospect. However, the proportions which mask cost accounted for in the costs of the entire lithography are rising. The increasing price of mask cost caused intense competition among global mask manufacturers. How to reduce mask cost and utilizing maskless lithography technology, the hot topic in lithography industry, have become an important subject for a lithography engineer to study. Based on ultraviolet light source and the digital gray-scale mask exposure technology, a new method of photolithography is proposed. First of all, we determine the overall program of DMD digital photolithography system, analyse and design each part of the system. On the whole, DMD digital photolithography system consists of upper-computer system, control system and optical system. Upper-computer system is the centre of control and administration. The whole system is supervised by host computer and subsystem is controlled by MCU respectively. Each MCU exchanges information and data through computer interface. Control system is composed of several subsystems such as master-slave computer interface, step motor drive, limit switch, DMD drive, solenoid valve drive subsystem. Illumination system, digital micro-mirror device (DMD) and projection objective made up optical system. Emitted from light source, light beam goes through illumination system and then illuminate mask (DMD). At the same time, DMD drive is performed and mask image is shaped. Then, the image is copied to light-sensitive photoresist by projection objective, which is coated on the substrate. Secondly, investigating key technologies such as the software design of upper-computer and control system, we set up experimental platform to carry out the relevant tests and experiments analysis. Moreover, we complement integration of the system and summarize system characteristics and difference. Finally, exposure experiments using light-sensitive photoresist are carried out. The results showed that the line width of submicron, steep sidewall can be realized by the designed system.

Low-energy ion beam erosion has been shown to be a promising alternative approach for generation of self-organized patterns on crystal surfaces. In addition to the removal of material from the surface due to sputtering caused by energy and momentum transfer from the incoming ions to target atoms, the interplay between sputter-induced roughening (result in a rough surface) and various surface relaxation mechanisms(result in a smooth surface) can lead to a wide range of well ordered patterns on the surface. In the experiments the Low-energy Ar+ ion beam were produced in a cleaning ion source on the magnetron sputter equipment from Belarus, and dot and ripple patterns have obtained at the different ion beam incidence. The FFT method is used to analyze the obtained nanostructures. In this paper results on self-organized patterns formed during low energy Ar+ ion beam erosion on Si surfaces are presented. It is analyzed the influence of ion beam parameters, such as the ion incidence angle, ion flux, and ion energy, to the self-organized nanostructures, and given the patterns formed on the Si surfaces in the case without sample rotation. The experimental results show periodic structures are depended deeply on the incidence angle of ion beams, and ripple patterns transferred from dot patterns with the increasing in ion beam incidence angle, which coincided with the Bradley-Harper theory of ripple formation.

DMFC (Direct Methanol Fuel Cell) is attractive as green energy with the characteristics of high energy conversion rate, lower carbon and emission, eco-friendly alternative energy. In DMFC, bipolar plate is one key component because of its high performance requirements, the bipolar plate nearly always makes about 60% contribution to the cost of all fuel cell, seriously affected the commercialization progress of DMFC. Furthermore, the flow channel design and arrangement in bipolar plate has a great influence on water and heat management, distribution of reactants and smooth resultant discharge. So the DMFC bipolar plate material and flow channel processing technique obtains more concerns. After introducing the bipolar plate structure and its functions, it points out that the bipolar plate material nowadays mainly involves the graphite materials, metals and composite. Then the corresponding preparation method, advantages and disadvantages of these three kinds of bipolar plate materials are analyzed. With the rapid development of Micro and Nano-technology and the demand for electricity supply of MEMS (Micro Electro Mechanical systems, micro-energy sources have been the focus, resulting in the miniaturization DMFC (μ DMFC). As the micro-bipolar plates has to survive the severe rugged working environment, such as high temperature, deep-etching, multi-field and alternating pressure), which challenges the material selection, flow channel configuration, processing method and precision. Therefore, hard-to-deform material such as titanium alloy is the preferred material for micro-bipolar plate. However, the new processing method has to be initialized for hard-to-deform material. This paper introduces the traditional and advanced processing methods of μDMFC bipolar plate. The existing problems of the DMFC bipolar plate material selection and processing are analyzed. We initialized one new technique that combines the laser-assisted heating method and micro die-pressing. The laser functions as the heater to warm up the micro sheet metal to reduce its forming force and improve the formability of hard-to-deform materials, which increase the possibility of die-pressing micro-bipolar plate in one stroke. It also means the potential prospect of processing of micro-channel.

Some primary simulation results on the electromagnetic polarity of asymmetrical metal nanoshells are introduced. Influencing factors, including nanoparticle parameters such as ellipsoidal coronal thickness and incident field characters such as polarization direction, are studied. By optimizing the parameters, a nanoparticle with stronger electromagnetic polarity and higher energy absorptivity could be obtained, which provides a way to control its behavior. The cluster model consisting of asymmetrical metal nanoshells are also discussed.

A coupled thermo-mechanical model of Ultrasonic Torsional Vibration Assisted Micro-milling (UTVAM) was established with ABAQUS, the primary cause which leads to a decrease in cutting force after adding Ultrasonic Torsional Vibration (UTV) to micro-milling was analyzed. Micro-milling with and without UTV were both carried out on the self-designed UTVAM experimental system, using forged aluminum alloy. Single-factor method was used to analyze the influence rules of cutting parameters such as spindle speed, feed per tooth and depth of cut on cutting force. It was found that feed per tooth plays a more important role than other parameters, a smaller feed per tooth can have a better effects on reducing of cutting force in UTVAM.

This paper introduces a magnifying lens group base on actual conditions. It is can be used in the detecting system to gate the magnified image of the energy distribution of the transmission light through the fiber. The magnification of the lens group is about eight. Image is received by a CCD. The lens is designed by using the software ZEMAX. The paper introduces the process of the lens designing. It analyses with great emphasis the error witch includes the primary aberration balance, installation accuracy and other influencing factor of the whole system.

Micro-opto-electro-mechanical systems (MOEMS) has prominent advantages over conventional optical devices, such as smaller, lighter, more stable, lower cost and power consumption. It has been widely applied in the last few years. This paper presents a micro spectrometer based on torsional MEMS grating with micromachining process. As a diffractive component in the micro spectrometer, the torsional MEMS grating is actuated by electrostatic force to scan the spectrum. In contrast to common linear detector arrays with stationary diffraction grating and non-fixed grating rotated by stepper motor to scan spectrum used in most micro spectrometer, MEMS-based spectrometer is dynamically controllable, and has no mechanical moving parts with small size. ZEMAX is used for design, optimization, and simulation analysis of the micro spectrometer with multi-configurations in the cross Czerny-Turner optical system. The results indicate that torsional MEMS grating operates at a torsion angle of ±3 degree, the spectrometer can scan spectral range of 800-1600nm in NIR (near infrared), spectral resolution is around 10 nm, and the whole spectrometer has a volume of 80mm×55mm×30mm. The study provides an initial theoretical foundation for the further development and design.

While the length of polarization period in the periodically poled (PP) waveguides has manufacturing errors (MEs), the impact of this errors on Quasi-Phase-Macthed (QPM) frequency doubling efficiency (FDE), and that of polarization period Λ0 and length of the waveguides at the direction of transmission beams on ME tolerance, which are all theoretically analyzed. The results show that with the ME increasing, FDE decreases rapidly. And the ME tolerance of PP waveguides is inversely proportional to the length of waveguides and is directly proportional to the polarization period Λ₀. These results provide a theoretical basis for choosing material of periodically poled crystal (PPC) and controlling MEs.

According to the focal depth and work environment of a space camera, a focusing mechanism is designed, which consists of precision screw ball transmission and linear bearing guidance and accuracy improving. The dynamic- strikeresistance, adaptability to temperature and vacuum are considered into the reliable design method. Furthermore, the linearity error, the structure stability and the mechanism work situation in high and low temperature are tested. The result is that the linearity error of the mechanism is less than 0.003mm, and the sway error of vertical way and level way of the mirror is less than 20". The linearity error of the mechanism and the sway error of the mirror remain unchanged after vibration test. The mechanism can work in the complex space environment.

Gold nanoparticles have found broad applications in nanomaterials and nanobiotechnology, but generally they are considered difficult to trap stably. In this paper, numerical studies are carried out to show that the main forces on the gold particles in optical tweezers. The results show that a stable trap for gold nanoparticles can be formed only when the parameters of laser wavelength, laser power, particle size and numerical aperture are properly selected. Keywords: gold nanoparticles, optical tweezers, gradient force, scattering/absorption force

In this paper, we describe a new fabrication process utilizing polydimethylesiloxane (PDMS) and polyester (PET) as a sacrificial substrate for fabricating free-standing SU-8-based nanofluidic system. The soft substrate permits SU-8 UV cured patterning and layer-to-layer bonding, and allows the SU-8 structures to be easily peeled off from the substrate after complete fabrication. In the process, PDMS-on glass is used as a handling wafer, on which SU-8 based trenches is imprinted by a flexible film mold using low-pressure nanoimprint lithography. The reservoir pattern of SU-8 is fabricated on the bonding layer, in which PET serves as substrate. The nanochannel is sealed by optimized bonding process, which is flexible and easily controllable with the use of soft substrate as a sacrificial layer. After bonding process, PDMS and PET could be easily peeled off from nanaofluidic system. The SEM results shows that the height of the fully enclosed nanochannels will be about hundreds nanometer. Large area of free standing SU-8 structure layers are successfully fabricated and peeled off from the soft substrate layer as single continuous sheets.

In this paper, we present a novel method for the fabrication of high density pattern in PET foils employing nanoimprint lithorgraphy. The temperature and pressure dependence on the imprinted pattern were investigated. Well resolved PET nanopatterns (sub-100nm resolution) were transferred successfully. It is observed that the grating with different trench depths will demonstrates corresponding changes of diffraction intensity distribution. The grating imprinted in PET foils could broader applications in the manufacture of nanophotonic structures owing to its excellent flexibility and transparency. Based on the optimized imprint process, a novel method for the fabrication of phase gratings and nanochannels is presented. This developed process can find broader applications in the manufacture of nanofluidic channels and other nanophotonic structures.

A temperature controller is designed to stabilize the temperature of a laser diode in the Spaceborne Fourier Transform Spectrometer. The principle and construction of the temperature control scheme are analyzed in this paper. Experiments are setup and data are obtained. It is found that the temperature stability is better than 0.01 k.

Based on DMD-lithography system, the mapping relation between gray scale and photoresist relief has been investigated. We obtain DMD reflectivity of different gray scale by experiment. Testing curve shows the light modulation of DMD is nonlinear from 0 to 255. However, the testing curve shows local linearization as well. The modulation of DMD is approximately linear from 40 to 130 and from 160 to 230. When designing the gray-scale mask, we should choose the gray scales in the same linear region to satisfy the requirement of multi-step relief. After being modulated by DMD, the reflection with mask information passes through the reduction projection system and images on the photoresist. After development, the photoresist relief can be formed. By comprehensively considering the influence of all parts on lithography, the exposure model is set up. We calculate the gray tones of 4-step and 8-step elements respectively according to the model. Experimental results show that the exposure model is reasonable and correct. The establishment of exposure model has reference value for the precise control on relief depth.

A theoretical study of transmission color filters with double metal layers for the visible spectrum is presented. The device consists of five parts: the transparent substrate, the dielectric grating, the first metal layer, the second metal layer and the cover dielectric layer. The first metal layer is disposed in the trench of the dielectric grating. The second metal layer, having the same thickness as the first metal layer, overlies on the top surface of the dielectric grating. And the cover dielectric layer is formed on the metal layers. By using rigorous couple-wave analysis (RCWA), the transmission characteristics are analyzed as a function of the duty cycle, the thickness of the dielectric grating, the thickness of the metal layers and the period. Based on the simulation results, a high-performance color filter is designed by optimizing the structural parameters. The grating periods are 280, 220, and 170nm for the red, green, and blue filters, respectively. For the red color filter the center wavelength was 650nm and its corresponding transmission 84%, for the green color one the center wavelength was 550 nm and its corresponding transmission 83%, while for the blue color one the center wavelength was 440nm and its corresponding transmission 83%. The bandwidths of the filters are about 100nm. Accordingly, the color filters not only perform better in filtering light but also produce high color purity. Additionally, each color light has high transmission. They are suitable for filtering in liquid crystal devices.

We present a high-efficiency broadband grating coupler for coupling between silicon-on-insulator (SOI)waveguides and optical fibers. The grating is only 14 μm long and 11 μm wide, and the size of the grooves is optimized numerically. For TE polarization the coupling loss to single-mode fiber is below 1 dB over a 35-nm wavelength range when using SOI with a two-pair bottom reflector. We used Focused Ion Beam (FIB) processing methods to fabricate the grating structure.The tolerances to fabrication errors are also calculated. The diffractive grating structures are designed to be inherently very directional by adding a silicon overlay before grating definition. 57% coupling efficiency at a wavelength of 1.54 μm is experimentally demonstrated on devices fabricated used FIB. By optimizing the grating parameters, we theoretically show that 83% grating output coupling efficiency can be obtained for a uniform grating structure.

To achieve high uniformity in large area on the mask of deep ultraviolet micro-lithography lens, a deep study of DUV micro-lithography illumination system is expanded in both theoretical and experimental aspects in this paper. Characters of different illumination structures and mode are introduced. Then an applicable illumination mode according to the requirements is selected. At the same time, two kinds of removing the uneven illumination ways--fly-eyes and optical tunnel are studied. After that, according to the large numerical aperture requirement, a refractive illumination system is designed with software ZEMAX. In this system, methods are used to reduce the number of the aspherical mirrors. The system is optimized to meet the requirement of large illumination area on the mask. Then by using the software of TracePro, the optimized system modeling and calculate illuminance on image plane are created and the uniformity of the image plane is analysised. The result shows that the uniformity of the image plane and the size of light spot basically satisfied the requirements, and having great feasibility in DUV micro-lithography illumination system.

The three novel methods of eliminating the grid effect caused by space duty cycle of Digital Micromirror Device (DMD) based on the DMD technique of maskless lithography are proposed, which are limiting the numerical aperture of projection objective, utilizing diffractive optical element arrays and using phase controlled beam shaping elements arrays. The physical mechanism of the grid effect is studied. The principles of three methods are analyzed and the experimental project about limiting the numerical aperture of projection objective, diffractive optical element arrays and phase controlled beam shaping elements arrays are proposed. The experimental results are given and the similarities and differences of the three methods are compared and analyzed. The experimental results indicate that these three methods can clear up the grid effect caused by space duty cycle of DMD. The research results will provide the references for improving the quality of maskless lithography device.

The method for designing diffractive microlens with micro-nano-scale structural features, through iterative angular spectrum algorithm, and fabricating diffractive microlens by single-step photolithography and a wet etching process, based on standard micro-nano-technology, was presented. Surface morphology testing shows that the diffractive microlens fabricated is composed of multi-step continuous relief structures with the feature height in the micrometer range, the distribution of the surface micro-nano-structures is circular symmetry, and the transition between the circular rings is smooth. A large number of fine structures with micro-nano-scale features can be clearly observed in the scanning electron microscope on the surface of the diffractive microlens. Surface roughness data tested shows that the surface roughness of fabricated diffractive microlens is in the nanometer range, which has reached the level of optical mirror. The optical aperture is in the micrometer range. The characteristics of the micro-structures on the surface and the optical aperture can be set and arranged flexibly by the iterative angular spectrum algorithm, according to the characteristics and parameters of the incident and outgoing beam. The results of optical characteristics measurement show that the diffractive microlens can focus incident red laser into a very small bright focal spot, and the phenomenon of focusing and defocusing is obvious. The analysis of beam quality shows that the intensity distribution and size of the focal-spot is in accord with pre-calculated results. The fabricated diffractive microlens indicates a very high diffraction efficiency. The experimental results demonstrate that the performances of the diffractive microlens can be further improved by modifying the design algorithm and optimizing the manufacture craft.

The deformable mirror (DM) is a critical optoelectronics component of the hyperspectral imaging system for food detection. It is very significant for the deformable mirror to design the best support structure with high dynamic stiffness. Based on the finite element analysis method, this paper discusses the DM support structure's mechanical principle and carries out optimal design. Three kinds of DM support structures with different sections are selected to compare their resonate frequencies. The type of the support structure with larger resonant frequency is picked up, then an optimal design solution has been introduced to determine a group of rational structure parameters which improve the resonate frequency of the support. Finally, the validity simulation analyses including random vibration and harmonic response are carried out to demonstrate that the optimization method is effective to improve the performance of the DM support structure of the hyperspectral imaging system for food detection.

To alleviate the difficulty in controlling the profile of the photoresist grating mask, advanced segment motion algorithm has been applied to simulate and analyze the evolution of the surface contour in ion beam etching. The simulation indicates that the combination of ion beam etching and reactive ion beam etching can effectively control the duty cycle of the holographic ion beam etching gratings. This has also been validated by the fabrication of four kinds of gratings with different periods (6.66μm, 3.33μm, 2μm, 1μm). This finding contributes to the fabrication of the holographic ion beam etching gratings because it helps to simplify the holographic exposure and development.

μResearch of negative-index material (NIM) is a very hot developing research field in recent years. NIM is also called left-handed material (LHM), in which the electric field [see manuscript], the magnetic field [see manuscript] and the wave vector [see manuscript] are not composed of a set of right-handed coordinates but a set of left-handed coordinates. Thus the action of electromagnetic waves in both left-handed material and right-handed material is just the opposite, for instance, the negative refraction phenomenon, the inverse Doppler effect and so on. Here we report the explicit result of the inverse Doppler effect through a photonic crystal (PC) prism at 10.6m wavelength for the first time, and the result we get from the experiment is much similar to the theoretical analysis we have deduced before. During the experiment, the CO₂ laser is used as a light source, and the PC prism is used as a sample, which can move a tiny distance (1mm) uniformly with a translating stage. Based on the method of optical heterodyne, we let the emergent light from the output surface of PC prism and the reference light from light source interfere at the surface of the detector. When the translating stage moves towards the detector, the optical paths in the PC prism will be changed, and then the Doppler frequency shift will be generated. Though several different samples have been tested repeatedly, the results we get are extraordinarily similar. So we can be sure that the inverse Doppler effect really exists in the NIM at optical frequencies. To our best knowledge, this is the only experimental verification of the inverse Doppler effect in the NIM at optical frequencies at home and aboard.

The relative position of mask and wafer can be reflected by the variation of the spatial phase in the alignment method basing on spatial phase of fringe pattern, through spatial phase imaging of grating modulation. The relative displacement of mask and wafer can be obtained from spatial phase demodulation of fringe patterns to carry out the alignment process. Generally, the windowed Fourier transform (WFT) is representative method for spatial phase demodulation of the fringe pattern. It is robust and accurate, but it is computational redundant for the alignment of nanolithography. This paper presents a phase demodulation method which has good accuracy and can be carried out in real time to meet the need of the alignment of nanolithography. This method is improved on the basis of the traditional WFT. The fast Fourier transform (FFT) is introduced to WFT and the phase is computed by integrating the phase gradient which is extracted directly from the fringe pattern through generation of the adaptive windowed Fourier elements. These two improvements can individually reduce the computation time for spatial phase demodulation of fringe pattern. The theoretical background and the principle of the algorithm of fringe pattern analysis are proposed. Numeric computation indicate that this method is of high accuracy and computational efficient for fringe pattern analysis, which show high significance for application of alignment of nanolithography.

Surface Plasmon polaritons are electromagnetic waves that propagate along the surface of a conductor, usually a metal. It is shown that the gain-assisted metamaterial can compensate for the intrinsic absorption loss in metal. In this paper, the propagation of surface plasmon polaritons on gain-assist metamaterial system is investigated. As an example, nanolithography has been considered by using optical proximity exposure in the evanescent near field of gain-assisted metamaterial layer. The evanescent waves carried the detailed information of the object which was defined by the high space frequency of the mask. With the enhancement of surface plasmon polaritons and gain-assisted metamaterials system, the evanescent waves can be propagated to a relatively far distance. Numerical computations by finite element analysis shows that better optimization of the gain-assisted metamaterials system can further improve the resolution. Experiments will be developed to prove the simulation by using a modified i-line aligner. The computation result shows it will be an alternative nanolithography technique for the next generation lithography.

With the integration of large scale integrated circuit devices improved, the requirement on resolution of Lithography has been enhanced day by day. The shortening of wavelength of light source and the augment of numerical aperture of projection objective make the effective depth of focus greatly reduced. The aggrandizement of wafer size and exist of focusing error make it clearly that traditional focusing methods cannot meet the harsh requirements of Nano- Lithography any more. Therefore, we need to develop new focusing technologies further. Aiming at the weak output signal of photodetector in nano-scale real-time focusing technique, this paper puts forward an innovative way in which we can make use of dual-phase lock-in amplifier to detect, amplify, filter and demodulate the signal. After a series of post-processing, we can get the defocusing amount of the wafer to make sure whether it is within the scope of effective depth of focus, for the purpose of assuring the exposure quality. We mainly use Simulink tools in Matlab to simulate the scheme model. From the simulation results we can see that dual-phase lock-in amplifier technique can extract the defocusing signal which we cares about excellently, and it does not rely on phase shifter. Compared with traditional methods, this method can obtain the defocusing signal more accurately. It helps to improve focusing precision significantly and lay a theoretical foundation for practicality in the near future.

A simple and new system for measuring the diffraction efficiency of large aperture gratings at littrow angle is established in this paper. The reference grating Po, double beams and timer with shutter have been draw into the system for eliminating the impact of polarization and stray light, fluctuation of incident light, and the fatigue of photodetector. A program is designed to scan, measure and calculate the diffraction efficiency of the gratings automatically. The diffraction efficiency accuracy measured for the gratings is increased by ~1% with this system. To achieve more measured accuracy, additional beam of reflection light should be imported.

It is well known that machining induced residual stresses can seriously affect the dimensional accuracy, corrosion and wear resistance, etc., and further influence the longevity and reliability of Micro-Optical Components (MOC). In Ultrasonic Torsional Vibration Assisted Micro-milling (UTVAM), cutting parameters, vibration parameters, mill cutter parameters, the status of wear length of tool flank are the main factors which affect residual stresses. A 2D model of UTVAM was established with FE analysis software ABAQUS. Johnson-Cook's flow stress model and shear failure principle are used as the workpiece material model and failure principle, while friction between tool and workpiece uses modified Coulomb's law whose sliding friction area is combined with sticking friction. By means of FEA, the influence rules of cutting parameters, vibration parameters, mill cutter parameters, the status of wear length of tool flank on residual stresses are obtained, which provides a basis for choosing optimal process parameters and improving the longevity and reliability of MOC.

As the critical techniques of lithographic system, the nano-positioning techniques, including the wafer-mask alignment, gapping between wafer and mask and wafer focusing, are of great significance to the improvement of resolution of the projection lithography and the proximity nanolithography, such as X-ray lithography, nanoimprint, and zone-plate-array lithography etc. This paper presents a scheme based on grating modulation and spatial phase imaging. The relative move and gap variation between mask and wafer can be associated with the shift or phase variation of fringe pattern and obtained simultaneously. Two gratings with slightly different periods are adopted as alignment marks and gapping marks on wafer and mask. Fringes with period that is inversely proportional to the difference of periods of two gratings occur in the superposition of two grating marks. First, the theoretical background is introduced and the mechanism of alignment gapping is detailed. Next, the scheme and framework of alignment and gapping method is constructed. Finally, numeric computational and experimental results indicate that the displacement detectivity at nanometer or even sub-nanometer level can be realized in this scheme.

As a key technology in lithographic system, the wafer stage is a six-degree of freedom and long stroke movement platform whose movement and positioning accuracy are up to nano-scale, and it involves precision machinery, precision measurement, automation and materials science in one complex system. In the lithography process, the function of the stage includes: wafer transmission, alignment, focusing and leveling, scanning exposure and so on. Positioning accuracy of the stage directly affects the alignment accuracy, as well as focusing accuracy, thus affecting the improvement of lithographic resolution as a whole. For the rapid increasing in chip integration, the chip makers acquire higher throughput of the lithographic system, under the demand, there has been dual-stage technology, i.e., in one lithographic system, there are two wafer stages, which separately locates at measurement position and exposure location. They run independently and in parallel, when the measurement and the exposure are completed, the two stages exchange their positions and functions. The dual stage technology not only significantly increases the yield, but also improves the measurement accuracy in focus detection. Focusing and leveling in dual stage is different from that in single stage. In this paper, combination of grating-based focus detection and dual stage technology is used to introduce leveling and focusing in dual-stage system. The principle of focus detection, the way for height information transforming to the wafer leveling data, as well as the servo of focusing and leveling at exposure location are carried out in detail.

In the analysis of optical spectrum, it is an effective means to construct the model of analysis and calibration by selecting proper wavelength data points, which can overcome the influences negatively produced by such factors as instruments, personnel and impurity in the measure of substances, as well as to improve the analytical precision of micro spectrometer system. This is particularly the case with multiple components. The reciprocal effect between multiple components appears to be more necessary than ever in involving in the selecting the wavelength data points in the construction of the model. The paper discusses the application of chaos optimization algorithm in the spectral wavelength selection on the basis of an overview of the basic theory of chaos optimization algorithm and brings forward a method of wavelength selection based on parallel binary chaos optimization. In the end, this method is illustrated with examples by adopting the computer simulation.

An optical modulation method based focus and level scheme is presented for optical projection lithography. The main parts of the focus system are analyzed respectively. Several kinds of modulation methods are adopted to realize nanometer resolution, including grating modulation, polarization modulation and optic-elastic modulation. The grating modulation is realized by imaging objective grating to the surface of modulation grating and then the modulation light is sent to polarization part. The polarization modulation is based on birefringence which can divide optical signal into two parts and each part represents the position and focus error of silicon wafer. Two or more equipments can implement wafer leveling. By introducing optic-elastic modulation, high signal-to-noise is obtained. Analytical result indicates that focusing resolution at nanometer level can be realized.

Computers, mobile phones, cameras and video equipment and other electronic products, Moving in the light, thin, small, high speed, high reliability, multi-functional aspects of development, Namely, 3G technology and the SOC of. Therefore, the various components of the packaging technology have become increasingly demanding, Electronic components of residual stress after encapsulation and the use of temperature changes during, Body will be made electronic packaging warpage, Seriously affect the quality of the product. Therefore, to establish a set of micron, sub-micron-level detection method for testing. In this paper, Moiré fringe method to measure warpage of electronic packages body volume, Was first proposed application of Rayleigh-Sommerfeld diffraction theory, Proof presented in this paper with a small spacing diffraction grating problems arising from the assumption can be overcome, Greatly improved the precision deformation measurement of electronic components.

Kevlar fiber-reinforced epoxy (KFRE) composites are widely used in the fields of aerospace, weapon, shipping, and civil industry, due to their outstanding capabilities. In this paper, mechanical properties and damage behaviors of KFRE laminate (0₂/90₂) were tested and studied under tension condition. To precisely measure the tensile mechanical properties of the material and investigate its micro-scale damage evolution, a micro-image measuring system with in-situ tensile device was designed. The measuring system, by which the in-situ tensile test can be carried out and surface morphology evolution of the tensile specimen can be visually monitored and recorded during the process of loading, includes an ultra-long working distance zoom microscope and a in-situ tensile loading device. In this study, a digital image correlation method (DICM) was used to calculate the deformation of the tensile specimen under different load levels according to the temporal series images captured by an optical microscope and CCD camera. Then, the elastic modulus and Poisson's ratio of the KFRE was obtained accordingly. The damage progresses of the KFRE laminates were analyzed. Experimental results indicated that: (1) the KFRE laminate (0₂/90₂) is almost elastic, its failure mode is brittle tensile fracture.(2) Mechanical properties parameters of the material are as follows: elastic modulus is 14- 16GPa, and tensile ultimate stress is 450-480 Mpa respectively. (3) The damage evolution of the material is that cracks appear in epoxy matrix firstly, then, with the increasing of the tensile loading, matrix cracks add up and extend along a 45° angle direction with tensile load. Furthermore, decohesion between matrix and fibers as well as delamination occurs. Eventually, fibers break and the material is damaged.

Micro Pitch-tunable Grating based on microeletromechanical systems(MEMS) technology can modulate the grating period dynamically by controlling the drive voltage. The device is so complex that it is impossible to model and sumulation by FEA method or only analysis macromodel. In this paper, a new hybrid system-level modeling method was presented. Firstly the grating was decomposed into function components such as grating beam, supporting beam, electrostatic comb-driver. Block Arnoldi algorithm was used to obtain the numerical macromodel of the grating beams and supporting beams, the analytical macromodels called multi-port-elements(MPEs) of the comb-driver and other parts were also established, and the elements were connected together to form hybrid network for representing the systemlevel models of the grating in MEME Garden, which is a MEMS CAD tool developed by Micro and Nano Electromechanical Systems Laboratory, Northwestern Polytechnical University. Both frequency and time domain simulation were implemented. The grating was fabricated using silicon-on-glass(SOG) process. The measured working displacement is 16.5μm at a driving voltage of 40V. The simulation result is 17.6μm which shows an acceptable agreement with the measurement result within the error tolerance of 6.7%. The method proposed in this paper can solve the voltage-displacement simulation problem of this kind of complex grating. It can also be adapted to similar MEMS/MOEMS devices simulations.

A novel atomic force microscope (AFM) system was constructed based on an air slide, an air spindle and a probe unit. It can carry out high-speed and large-area measurement for micro-structure surface with three scanning strategies of radial scanning, concentric scanning and spiral scanning. Using the AFM system, the micro-structure surface of a grating was measured with these scanning strategies. The measuring capability of them was researched by the experiment and the three measuring results were contrasted. The results show: compared with the other two scanning strategies, the spiral scanning mode can bring the best measuring image of the micro-structure profile, and it also spend the shortest time, it is only 50 seconds to finish scanning an circular area with 1 mm diameter.

Gratings as important spectral components have been employed in various optics applications, such as spectral analysis, filtering, dispersion compensation, sensing and so on. However, the physical structure of gratings produced by conventional technologies can not be alterable, this limits their applications under some specific requirements. Fortunately, MEMS technology breaks through that restriction, an interdigitated comb structure has been demonstrated in this paper. The comb structure has two sets of comb gratings; one is stationary and the other is movable in the horizontal plane. By driving the movable comb gratings, the intensity of diffraction will be adjustable. Under the condition of Fraunhofer approximation, the broadening extent of zero-order diffraction is monotonically increasing with the longitudinal displacement, and the relation between the intensity of first-order diffraction and the lateral displacement is a cosine squared function. A displacement sensor based on movable comb structures is presented and detailed analysis on sensitivity factors is given.

The key technology of micro optic gyroscopes (MOGs) is to fabricate low-loss waveguide and use coupling technology to form reciprocal structure. The main topic in this paper is to study the coupling structure of MOG's spiral-ring waveguide. Using for the reference of fiber's low-loss character, the fiber-preform project is chosen as optimization means. According to the singlemode conditions, the width and thickness of rectangle waveguide can be calculated. The bend loss waveguide can decrease by means of introducing an offset at the junction of two waveguides and etching groove at the outside of bend waveguide. In this article intersection waveguide is designed to reduce the difficulty of coupling processing. Light in-and-out port coupled at opposite side is choosen for machining easiness in experiment.What's more, the edge-coupling technology being put forward to keep light transmit along the same rotary direction. An efficient means is introduced, which uses angle 45°to reflect the light to couple two waveguide at inside-end or outside-end, and outside-end coupling is chosen for processing convenience in the design. In experiment, the waveguide be fabricated by thick photoresist AZ4620, etched by RIE, When the angle of wafer and ion is set 85°, the angle of one sidewall can be etched almost 45°. It's benefit to design the coupling structure of MOG's spiral-ring waveguide.

This paper proposed the pyramid microstructure (PYM) used on the base of the light guide as the micro-optical components to replace the conventional diffuser dot made by direct etching on the steel stamper. The PYM is made by MEMS technology, which uses silicon wafer as original mold of PYM and to replicate it on Ni micro-mold by using electroforming method. The effective optical design tool is used to find the optimal distribution of the PYM, which integrates the random microstructure generation scheme developed based on the molecular dynamics method and the optical commercial software. The SEM images show the intact PYM can be produced on the Si micro-mold and replicated fully on the Ni micro-mold by the electroforming process. The intact PYM on the base of the light guide can also be produced by the injection molding showing the complete transformation of the Ni micro-mold to the light guide. The luminance measurement of a 2.4 inches backlight module with 4 LEDs shows the average luminance of 4769 nit with 86.3% uniformity for the PYM on the base of light guide, which is 10% higher than that for the diffuser dot microstructure.

The nanoshell optimization for obtaining large electromagnetic absorption efficiency is studied, and the structure with photo-thermal polarity is studied. It is found that the resonance wavelength is determined mainly by diameter ratio of core /shell, the energy absorption peak shifts to shorter wavelength by increasing the shell thickness. And as the particle size increases, absorption peak increases significantly first and then decays. The electromagnetic losses for single particle and for 3×3 planar arrangement are analyzed. The individual nanoshell in the arrangement shows unique distribution with polarity.

The bifocal microlens are novel optical components, which have the capability of producing two focal points along optical axis. They have potential application in readout of dual-layer disks, optical tweezer, optical coherence tomography and microfluidic system. In this paper, the design for the bifocal microlens has been presented. The distortion of the pattern transfer process in the thick film lithography has been analyzed. The modified grayscale mask method has been introduced to compensate the distortion of the pattern transfer process. The simulation for fabrication of the bifocal microlens in the thick film lithography has been performed, which shows that the simulated profile is closely consistent with the designed one. Through our proposed method, the bifocal microlens with high profile quality can be obtained, and consequently this can greatly improve its optical performance. Furthermore, the fabrication process is relatively easy and the cost is low, which is favorable to the future application of the bifocal microlens.

The paper presents and discusses several prevalent methods for lithography alignment, and then describes and emphasizes the principle, mechanical structure and alignment procedure of the bottom-side alignment (BSA) system for deep-exposure lithography tool. Also, the error source degrading the precision of the alignment system is analyzed. Other related techniques and methods are provided. In the end, the aligned reticle image shows that the system is proved to be stable, reliable and capable of meeting the required precision when it is applied to DUV double-side deep-exposure mask aligner.