In this paper, first of all improved techniques are described to measure packaged MEMS or MOEMS surfaces through- transmissive-media (TTM) at higher magnifications. Secondly, a universal housing is presented for TTM-objective line and for different material and thickness of glass. Finally, the measurement results for low and high magnifications will be given for dispersion-compensated objectives, as well as some MEMS application examples.

We present measurements and numerical findings of resonance effects in aluminum metal gratings on fused silica substrates. The spectral characterization measurements of the gratings are done with white light in the wavelength range of 600nm up to 1600nm. Nonlinear effects have been studied with a fs-laser system at the resonance wavelength of the gratings. The metal layers of the gratings are 20nm to 40nm thick, the gratings period is 500nm or 1000nm and the narrow gaps between the metal stripes consist of about 8nm thick aluminum oxide stripes. These structures were produced with a special micro structuring process and coating technique. Numerical modeling shows that light can pass through these gratings for a characteristic resonance wavelength. For fs-pulses we found the transmission to decrease for increasing pulse energy.

This paper summarizes some of latest developments by QED Technologies (QED) in the field of high-precision polishing and metrology. Magneto-Rheological Finishing (MRF) is a deterministic sub-aperture polishing process that overcomes many of the fundamental limitations of traditional finishing. The MR fluid forms a polishing tool that is perfectly conformal and therefore can polish a variety of shapes, including flats, spheres, aspheres, prisms, and cylinders, with round or non-round apertures. Over the past several years, QED's Q22 family of polishing platforms, based on the MRF process, have demonstrated the ability to produce optical surfaces with accuracies better than 30 nm peak-to-valley (PV) and surface micro-roughness less than 0.5 nm rms on an ever-widening variety of optical glass, single crystal, and glass-ceramic materials. The MRF process facilitates the correction of the transmitted wavefront of single elements and/or entire systems, as well as enabling the inducement of specific desired wavefront characteristics (i.e., other than making surfaces perfectly flat or spherical), which is beneficial for applications such as phase correction or other freeform applications. QED's Sub-aperture Stitching Interferometer (SSI) complements MRF by extending the effective aperture, accuracy, resolution, and dynamic range of a phase-shifting interferometer. This workstation performs automated sub-aperture stitching measurements of spheres, flats, and mild aspheres. It combines a six-axis precision stage system, a commercial Fizeau interferometer, and specially developed software that automates measurement design, data acquisition, and the reconstruction of the full-aperture map of figure error. Aside from the correction of sub-aperture placement errors (such as tilts, optical power, and registration effects), the SSI software also accounts for reference-wave error, distortion, and other aberrations in the interferometer's imaging optics. By addressing these matters upfront, we avoid limitations encountered in earlier stitching work and significantly boost reproducibility beyond that of the integrated interferometer on its own.

Because of the demand for better performance in optical systems, there's a continuing effort to find more efficient ways of producing large optics. FOERC's involvement in developing new techniques for the fabrication of large optical components has resulted in the AOMTIL (Advanced Optical Manufacturing Technology Integrated Line). The purpose of the AOMTIL is to demonstrate the novel manufacturing process and technology for large optics in modern optical system. The progress of AOMTIL is presented in the paper. There are mainly four parts in AOMTIL as follows, the ultra-precision grinding, deterministic figuring or polishing, perfect surface conditioning and precision optical metrology. The preliminary results of the AOMTIL show the possibility to yield more than 20 pieces large optical components per month and the advantages in achieving high accuracy. Optical flats larger than 500mm in diameter have been produced with flatness better than λ/10 peak to valley.

Non-equilibrium ionization plays a critical role in Z-pinch gas discharge produced plasma (GDPP) EUV source. However, the physics of the processes, plasma and surface discharges produced, magneto-hydrodynamic, photon radiation transport, and plasma-electrode interactions, which lead to EUV emission, is intrinsically complex. Many simplifying assumption are inevitable with numerical simulations, resulting in low-credibility outcomes. With the learning and generalization abilities, artificial neural networks (ANN) have been applied to model and optimize a Z-pinch plasma source, which is characterized with a experimental design at varied operational parameters including electric power input, applied voltage/current, pulse repetition, MPC parameters, electrode geometry, xenon flow rate as well as convention efficiency, EUV source size, radiation power etc.

A hydrofluoric acid (HF) bonding method has been applied for the thin film filters integration. The quality of bonding was examined by the evaluation of bonding strength and the observation of bonding interface. The bonding strength depends on the applied pressure and temperature during bonding. The maximum bonding strength was more than 10 MPa. High quality bonding interface was observed by scanning electron microscope and transmission electron microscope. A color filer array of red, green and blue (RGB) was designed to separate the white light. The filters were integrated into a glass body successfully by HF bonding. Its transmittance spectra were unchanged after heating at 450^oC for 20 hours. In addition, integration of filters was carried out to fabricate an optical demutiplexer for coarse wavelength division multiplexing system. It was confirmed that the integrated filter array acted as a demutiplexer.

Zinc sulphide (ZnS), a significant Infrared (IR) optical material, is applied to window, lens and dome in many optoelectronic systems where a suitable antireflection (AR) and protective coating is required to enhance the transmission. In this paper, the transmittance characteristics and deposition process considerations of AR coatings on ZnS substrate are investigated in detail. Through the theoretical analyses and real process experience of common materials such as magnesium fluoride (MgF₂), silicon dioxide (SiO₂) and silicon monoxide (SiO), and the deposition and environmental test of yttria (Y₂O₃) coating, an optimum 5-layer structure is finally employed, which consists of a bonding layer with ZnS substrate, thin Y₂O₃ film, and a 4-layer stack of germanium (Ge) and SiO as high and low refractive index coating materials, respectively. Then, experimental implementation of the AR design is presented, especially the deposition of Y₂O₃, Ge and SiO materials. The fabricated coating conforms to the tests of humidity, temperature shock, abrasion and adhesion given in the MIL-C-48497 environmental stability standards and shows an average transmittance of 96% for a given application in 3-5μm wavelength region with a peak beyond 98% at 4.2μm on 3mm thick ZnS substrate. Moreover, due to stable deposition process of Ge and SiO, better AR coating with higher spectral transmission can be easily designed and fabricated through more layers of Ge and SiO.

Firstly, a reverse synthesis method is outlined for the determination of the optical constants of infrared coatings from transmittance spectrum data by optimizing the physical thickness, refractive index and extinction coefficient, which can apply to all kinds of transmission spectra and do not rely on the existence of interference fringe patterns and the absorption of substrates. A lot of deposition experiments with the ion-assisted deposition (IAD) technique have firstly done about infrared optical materials ZnS, YF3, Ge and DLC (diamond-like-carbon), in order to obtain high dense and low absorbance layers in the 3-5μm and 8-12μm spectral windows. Using the reverse synthesis method, the refractive index and extinction coefficient of these materials have been obtained accurately. The appropriate deposition parameters and the problems from the deposition process are in detail discussed in this paper. YF3 has been then associated with ZnS and Ge layers so as to obtain antireflection coatings with high performance on Ge and Si substrates in 3-5μm and/or 8-12μm range. In addition, a novel multi-layer infrared AR coating utilizing DLC film as one of the low index films has also been developed for Si and Ge substrates. The optical performance is satisfied (average transmittance is no less than 97%, maximum transmittance is more than 98%, from 8μm to 11.5μm), which is better than that of a single film of one quarterwave DLC coating with interior surface multi-layer AR coated on Ge substrates. However, the adhesion between multi-layer AR coatings and DLC coating is not well, leading to coatings falling off from substrates after humidity test and moderate abrasion test, according to MIL-F-48497. Through a lot of experiments, a non-absorbing coating material has been found as bonding layer to solve this problem. The optical properties of three kinds of infrared coatings and the environmental and physical durability test results including high/low temperature test, abrasion test, salt solubility test, etc, are also in detail presented in this paper.

The low temperature control system of single photon detection device avalanche photodiode (APD) is researched. Avalanche photodiode is used for photon detector with high sensitivity. In order to reduce dark current, its operating environmental temperature needs to be lowered by a semiconductor thermoelectricity cooling apparatus. In accordance with the peculiarity of single photon detection system and the technology of semiconductor thermoelectric Peltier cooling, an APD cooling control system is designed and produced by properly selecting components and using some necessary control circuits. The accuracy and the lowest temperature of this control system can amount to 0.1^oC and -50^oC, respectively. Above all, the low temperature can be adjusted successively.

Recently, RB SiC as a two-phase mirror material has taken particularly attraction because of its readily formable to near-net-shape. But it is difficult to obtain high quality optical surface due to the polish rate differences between SiC and Si components. Typical defects, such as polishing scratches, pores and surface irregularities which are mostly caused by the inhomogeneity of SiC and Si phase distributions are easily detected. The solution is the addition of a thick coating to cover these surface defects which may be polished to improve the quality of optical surface. Two thick coatings, PVD Si and PVD SiC, were applied by RF magnetron sputtering in this paper. After a series of sputtering parameters optimization, both the coatings' surfaces show fewer defects than that of RB SiC after polished. Results from this PVD progress, the surface morphologies' changes in optimization and the surface defects after polished are presented.

V₂O₅ and Ta₂O₅ mixed powders were pressed as sputtering target. Ta-doped vanadium oxide thin films were deposited on SiO₂ substrates by modified Ion Beam Enhanced Deposition (IBED) method. The VO₂ film with a preferential orientation (002) was formed after post-annealing in nitrogen or argon atmosphere. The measurement results of resistance dependence on temperature indicated that the vanadium dioxide films showed a typical characteristic of phase transition. The phase transition temperature of the IBED VO₂ film doped with 3 atm.% Ta decreased from 68^oC to about 48^oC. The reasons why the Ta-doping decrease the phase transition temperature were as followed: the atom radius of Ta larger than that of V atom, which introduce strain in the grain; the replacement of When V⁴⁺ replaced by Ta⁵⁺ the ionic bond could elongate and introduce superfluous electrons in the d valence shell, then make the gap of d energy band to decrease.

Aspheric surface can be thought as being enveloped by a series of spherical surfaces with their centre on the same axis but having different positions. These spherical surfaces are tangent with the aspheric surface. A Φ600 CNC aspheric grinding machine with this novel operating principleis manufactured. The machine was reported in August 2005. We choose δ_p, ε and α_p as the key parameters of our grinding machine. δ_p is the distance between the cup shaped tool's bottom and the vertex of the aspheric surface. α_p is the rotational angle of the cup shaped tool. ε is the space angle of the cup shaped tool during the fabrication process of convex aspheric surface. This grinding machine can be used to fabricate a conic concave aspheric surface continuously about three hours. But we need change the cup shaped tool one time when we fabricate a conic convex aspheric surface in also about three hours. The grinding machine can also be used to fabricate high-order aspheric surface. In the last report we intoroduced that we used this machined fabricating a RC telescope system's primary and the secondary mirror. The PV-value is less than 5μm for the primary Φ350 concave hyperbolic aspheric surface which departure is about 55μm. The residual errors can be removed easily. This machine have been improved both the cup shaped tool and filter system. Using this grinding machine we have fabricated another Φ460 concave aspheric surface during the last month. The PV-values of these two mirrors are both less than 7μm. The aspheric grinding machine can be fitted for fabricating concave conicoids.

We present our experimental results on fabricating optical waveguides by laser micromachining, structure-light illuminating, and optical spatial dark solitons in iron doped lithium niobate (LiNbO₃:Fe) crystals. After that we propose a novel approach to fabricate three-dimensional (3-D) optical circuits in LiNbO₃ crystals by combining the three light-induction techniques listed above. By employing laser micromachining, a curved and a Y-branches waveguides are successfully fabricated. With binary and SLM-prepared optical masks, Y-branches and gradient planar waveguides are experimentally demonstrated. By utilizing one-dimensional (1-D) optical spatial dark solitons, planar, Y-branches, and square channel waveguides are formed. The results show that each of the three methods can be employed to write optical waveguides in LiNbO3 crystals. By combing the three methods, 3-D light circuits can be created in 45^o-cut bulk crystals by several procedures. Initially, a quasi-planar optical circuit is created in a thin layer of the crystal by structure-light illuminating with an optical mask. Then, a planar circuit is generated by utilizing a 1-D dark soltion. And then, form multi-layer planar circuits are formed by altering the positions of the crystal or writing beam. Finally, laser micromachining is used to link the different layers to form a 3-D light circuit. Furthermore, functional 3-D integrated optical system may be implemented by using the proposed approach.

Using pyromellitic dianhydride (PMDA) and bis(4-aminophenyl) ether (ODA) as monomer materials, the polyamic acid (PAA), a precursor of polyimide (PI), was synthesized. PAn was doped and modified with the polyamic acid by solution mixing method, and the modified PAn/PAA blend with good solubility and forming-film was obtained. Then uniform PAn/PI complex thin film with good forming-film and thermo-stability can be prepared by solvent casting and followed by thermal imidization process at the temperature of 150^oC-250^oC for 60 min. Conductance experiments showed the surface conductivity of PAn/PI thin films can raise to 10^-5S from 10^-10S and change with the increase of the content of PAA. IR and UV-vis spectra showed that it has a chemical doping reaction between PAn and PAA during mixing, and the absorption of PAn/PI complex films in UV-vis region appears red shift and the peak shape becomes broad. The degenerate four-wave mixing experimental results showed that the third-order optical nonlinear susceptibility χ⁽³⁾ of PAn/PI thin films can be markedly enhanced and the maximum χ⁽³⁾ can reach 8.85×10^-10esu, which presents good third-order nonlinear property.

The Mirror-Confinement-type Electron Cyclotron Resonance (MCECR) plasma source has high plasma density and high electron temperature, and it is quite useful for plasma processing, and has been used for etching and thin-film deposition. Carbon films have received much attention recently due to their interesting properties such as extreme hardness, high electrical resistivity, low coefficient of friction, superior mechanical properties, chemical inertness, biocompatibility, high transparency and chemical inertness, which are close to those of diamond. In this paper, the carbon films about 50nm thickness were deposited on Si (100) by MCECR plasma sputtering the sintered carbon target with the argon plasma, and its properties were studied. The bonding structure of the film was analyzed by using the x-ray photoelectron spectropscopy (XPS) and the nanostructure was evaluated with the high-resolution transmission electron microscopy (HRTEM). The tribological properties (friction coefficient, wear rate, and wear life) of the film are investigated by using the Pin-on-Disk tribometer under the conditions that the normal load is 1N and the sliding velocity is 0.05m/s. The nanohardness of the films was measured by using the nanoindenter under conditions that the maximum displacement is 30nm and the maximum load is 500μN. The surface morphology was studied by using the atomic force microscope (AFM).

Aspherical optics are more and more exploited in optical set-up since they reduce the number of components and therefore the overall size and weight of the system. Their manufacturing has been made easier by ion beam etching for many years. Nevertheless, the ablation rate has to be known accurately for each material and the degradation of the surface roughness has to be taken under control. Some examples of achievements will be shown. The main key feature is the knowledge of the original absolute shape of the surface to be figured. In some cases, interferometric measurement is not well suited and heavy to set up for high aspherical surfaces with deep sag. To avoid the drawbacks of interferometry measurements, a low cost scanning measurement device has been designed and built whose performance allows defining the topology of any surface up to 150 * 90 mm² area with an accuracy better than 80 nm. Perspective of extension to larger surface will be presented.

Machining of aspheres represents an extra field in the manufacturing of optical components. The deviation from the sphere has a big impact on machining and testing equipment, tools and technologies, achievable specifications and costs. The production of aspheres deals with special problems such as mid-spatial frequency errors, centering tolerances and slopes, not known in that degree from manufacturing of spheres. Over the past 20 years JENOPTIK Laser, Optik, Systeme GmbH has gained a wide experience of this application area. Recent results give a review on what is required to execute the transition from standard quality to high-precision aspheres, off-axis parts and free forms.

A new photoelectric model of silicon based position sensitive detector (PSD) is built and the formulas of the photocurrent and spectral response are got with it. The effect of every layer thickness and SiO₂ thickness to the spectral response is analysis and calculation. The spectral response of PSD is affected by the thickness of p layer mainly at short wavelength and by the thickness of the depletion layer mainly at long wavelength. With the results, a new silicon based near infrared two dimensional pincushion PSD is designed and fabricated. Some necessary tests show that the peak spectral sensitivity of our device is 0.626A/W at 920nm wavelength.

A novel polishing and shaping process called fluid jet polishing (FJP) is introduced in this paper. Different from classical polishing methods, the material is removed by collision and shearing actions between the abrasive particles and the work piece in FJP, and the classical Preston Equation does not represent the polishing process correctly. It is necessary to establish a new mathematical model to do this. By using monofactorial experimental method, the important process parameters of FJP including working pressure, processing time and the rotational speed of the work piece were investigated in experiments. Based on the experimental results, the expressions between the important process parameters and the amount of removed material were constructed through data fitting. And then we put forward a new mathematical model to describe the polishing process of FJP, and control the amount of removed material quantitatively. The construction of this equation is a theoretical basis to realize numerical controlled fluid jet polishing, and foundation of applying this technology to modern optical fabrication

Magnetorheological finishing (MRF) is a technique in which a magnetic-field stiffened ribbon of MR fluid is used to polish a workpiece. MR fluids are essentially suspensions of magnetizable particles immersed in a nonmagnetic fluid. These complex fluids show a unique ability to undergo rapid, nearly completely reversible, significant changes in their mechanical and optical properties upon application of an external magnetic field. The aim of this work is essentially to investigate the effect of microstructure and viscosity behavior of magnetorheological suspensions under the external electro-magnetic field. A viscometer equipped with a circular shape electro-magnetic coil around the testing tube is used. The viscosity of the MR fluids is experimentally studied with the change of the magnetic density. The microstructure and behavior of bending chains in MR fluids are observed by applying an electro-magnetic field.

This research investigates the diamond grinding mechanism of optical glass and the resulted surface and sub-surface by a novel ultra-stiff machine tool, Tetraform 'C'. During the grinding process, an acoustic emission (AE) sensor and a piezoelectric dynamometer were used to monitor the grinding process and the grinding force components correlating to different characteristics of the material removal transition. SEM and AFM microscopes were used to evaluate the ground workpiece surface topography and sub-surface integrity. The nano-indentation technique was applied to evaluating the ground glass surface properties in terms of nano-hardness and elastic modulus. The Experimental results show that for BK7, nanometric quality surfaces (Ra < 5 nm) with minimal subsurface damage depth (< 1μm) could be achieved with a relatively large diamond grit size (6-12μm) metal bonded grinding wheel at a high material removal rate, due to the ultra high closed loop stiffness of Tetraform 'C'.

Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

SiO₂/ZrO₂ gel films were derived from Zr-butoxide modified chemically with β-diketones and then mixed with Tetraethyl orthosilicate via Sol-Gel process. The obtained gel films showed an absorption band, in characteristic of the π-&pi* transition of chelate ring at around 334 nm, and its refractive index was changed from 1.463~1.647. The Si-O-Zr, Zr-O bands were detected by FTIR. The result indicated that SiO₂ and ZrO₂ integrated uniformly in the films on micro molecule magnitude. The negative tone gel films were irradiated with high pressure mercury lamp through mask and then leached in ethyl alcohol. The above process gave uniform surface-relief gratings of periods at 2.0μm. The present study had proved that the photosensitive gel films were versatile for the fabrication of micro optical devices

In general, the high resolution of a microscopy could be acquired by increasing the NA (numerical aperture) of lens, and simultaneously increasing the luminous flux. But many experiments shows: in turbid media, the NA of the lens we use is larger, the radius of focal spot is larger and the resolution decreases on the contrary. Because of highly scattering, there are different characters of focusing and propagation in turbid media .We simulate the process of photons motion in turbid media by means of Monte Carlo method according to a known model with representative parameter: changing the NA of lens in the program, the gray-scale images of the light spot in various layer are obtained. We also plot two figures; (1) distribution of the normalized light intensity versus the transverse axis; (2) the radius of light spots as a function of depth. In the figures: the trends of distribution of the normalized light intensity are coincident and centralized; when lens with larger NA is used, the normalized light intensity curve is further from the axis; it is also found the size of the focal spot is bigger and light beams focus in turbid media deeper. All above expound: the NA of the lens is larger; the radius of focal spot is larger in turbid media. In addition, it also suggests various factors including scattering, absorption and scalar diffraction etc must be taken into account when we choose the lens to focus in turbid media.

Computer-Aided Alignment (CAA) is an effective method for improving image quality of an optical system. This paper studies some key techniques of CAA for space telescope, including the mathematical model of CAA, the acquirement and processing of aberration data, the establishment of sensitivity matrix and the solution of misalignment. A numerical simulation of a space telescope has been performed to verify the ability and accuracy of the method.

The optimal exposure distances for 3-D optical waveguides induced by laser micromachining in LiNbO₃ crystals are theoretically and experimentally investigated. By solving the photorefractive dynamic equations, the optimal distances for waveguide fabrications are numerically specified when the focused laser beams scans along the different directions. The simulations show that the optimal exposure distance is not dependent on the scanning directions of the writing beam, but the index distributions of the fabricated waveguides are seriously dependent on them. When the writing beam scans the crystal along the axis c, optical waveguides cannot be fabricated efficiently. However, in this case, symmetric refractive index changes can be obtained, so called as sandwich illumination method. By scanning LiNbO₃: Fe crystal with a focused green laser beam, experimental demonstrations are performed. The light-induced index changes are measured by employing digital holography. The experimental results coincide with the theoretical analyses. Additionally, a curved waveguide is experimentally formed. The near field pattern and the results of the guiding tests show that the waveguide are successfully written in the LiNbO₃:Fe crystal.

Durham University's Centre for Advanced Instrumentation (CfAI) have developed a technique for fabricating monolithic multi-faceted mirror arrays using freeform diamond machining. Using this technique, the inherent accuracy of the diamond machining equipment is exploited to achieve the required relative alignment accuracy of the facets, as well as an excellent optical surface quality for each individual facet. Monolithic arrays manufactured using this technique, have been successfully applied in the Integral Field Unit for the GEMINI Near-InfraRed Spectrograph (GNIRS IFU), which was recently commissioned at GEMINI South. In this paper, we present details of the fabrication process and optical performance of these components. We will also briefly discuss how their implementation has facilitated the GNIRS IFU's opto-mechanical system design and subsequent integration and test, and highlight the resulting improvement in system performance.

A Microlens array is a critical component for optimizing display functions. With the increasing usage of display systems in photonic products nowadays, more attention is being paid to the research and development of fabrication technology for microlens arrays. Ultra-precision machining with a fast tool servo (FTS) is one of the leading methodologies for fabrication of high-quality optical microstructural surfaces. FTS is an independently operated positioning device, which provides an indispensable solution for machining optical microstructures with sub-micrometer form accuracy and nanometric surface finish, without the need for any subsequent post processing. The surface quality of an FTS machined surface depends largely on the selection of cutting conditions. However, the achievement of ultra-precision surface finishing depends greatly on the experience and skill of the machine operators. Determination of optimal cutting conditions can stabilize the quality of the fabricated microlens array. In this paper, the effect of cutting conditions such as depth of cut, feed rate, spindle speed and surface speed are investigated; and optimal surface roughness and surface profiles in ultra-precision machining with FTS can be observed.

One of the main factors driving ICs in complexity is the improvement in photolithography to print small features. The use of immersion imaging and resolution enhancement technology (RET) will extend the ArF lithography to produce small features. With the patterns size decreasing, the absolute CD variation has a bigger relative importance on small features. The process windows are used to see if a certain process is compatible with the dose and focus budget. We discuss the impact of illumination, numeric aperture, phase-shifting mask and polarized light on process windows using ArF immersion lithography to print line pattern exposed features in photo resist on 45nm node. The interaction between the process windows and illumination, numeric aperture, phase-shifting mask and polarized light are calculated using a full photo resist model. The analysis gives fundamental insight into the optimum conditions necessary for printing these patterns both individually and simultaneously. The results show that illumination, numeric aperture, phase-shifting mask and polarized light can contribute to the process capability. The dipole illumination system can enhance the process window about twice than that use conventional illumination. The process capability of semi-dense pattern is insensitive to optical parameters. The 100% attPSMs and altPSMs are strong phase shifting mask, so the process capability can be enhanced. By using the polarized light can enlarge the depth of focus about 4%~11% with specified exposure latitude. According to the rules of process windows, some methods to extend process windows are presented.

Model-based Optical Proximity Correction (MBOPC) is used to make systematic modifications to transfer a pattern's design intent from a drawn database to a wafer. This is accomplished by manipulating the shape of mask features to generate the desired pattern (design intent) on the wafer. MBOPC accomplishes this task by dividing drawn patterns into segments, then using a process model to manipulate these segments to achieve the design intent on the wafer. The generation of an accurate process model is very important to the MBOPC process because it contains the process information used to manipulate correction segments. When corrected data are written on a reticle, the faithful and well-controlled reproduction of the data on the mask is critical to realizing the desired lithographic performance. This paper will explore methodologies to improve model accuracy using mask fabrication data and process test patterns. Model accuracy improvement will be accomplished using intelligent sampling plans and representative mask structures. The sampling plan needs to identify critical device and process features. The test mask used to generate the process model needs to have test structures to gather process data. The test mask also must have test structures that can evaluate model quality by testing the extrapolation and interpolation of the model to data that was no used to generate the process model. These methodologies will be shown to improve final mask pattern quality.

A Very High Resolution Telescope (VHRT) is designed as a space-to-earth remote sensor and the polarization effect in this VHRT is analyzed in this paper. First, the theory of polarization effect is reviewed. Second, the Jones arithmetic of polarization aberrations in VHRT is presented. Then, CODE V software is used to realize the polarization ray trace in this system and the results of the polarization effect analysis are obtained. The output information includes the plot of Modulation Transfer Function (MTF), the plot of Point Spread Function (PSF), pupil map, relative illumination, illumination, distortion and Strehl ratio. Finally, effective methods to control the polarization effect in an optical system are given. According to the results of analysis, we have drawn the following conclusions. Polarization effect in an optical system shouldn't be ignored to improve the imaging quality; with the incident angle as small as possible to control the polarization effect. Coating design must be considered carefully for the optical design.

Silicon Carbide (SiC) has been recognized as a leading material for optical applications. In this paper, grinding of RBSiC using diamond wheels on surface milling machine under various grinding parameters was investigated. Examinations of ground surfaces reveal that surface roughness increases with increase of depth of cut and decreases with increase of burnishing time, but a further prolonged of burnishing time did not work obviously to improve surface quality. Values of surface roughness swing with increase of work-piece rotation speed and exhibit variety with the increase of the cumulate removal volume under different depths of cut. The Vickers hardness of ground RBSiC decreases with the depth of cut. Scanning electron microscopy (SEM) observation revealed that brittle fracture and plastic flow removal mode coexist during grinding process. The percentage of ductile-mode grinding area decreased with increasing of depth of cut.

Optical microstructures are very important for the realization of multifunctional optics and photonics devices. In the last decade, with the development of commercial femtosecond laser, it has been proven that micro-structuring with femtosecond laser pulses is an excellent tool for free design micro-fabrication of almost all kinds of materials. With the filament, spatially scanning and other methods, many types of 0 to 3-dimensional optical microstructures, including optical memory, waveguides, gratings, couplers and photonic crystals, were produced successfully inside a wide variety of transparent materials of solid state and also liquid state. Here we reviewed the proceeding of the micro-fabrication technology by femtosecond laser pulses in the last few years.

The ultra-weak photon emission is an intrinsic and spontaneous process in biological objects without any external excitation and is referred to as "biophoton emission". This paper reports the design of the rotation ellipsoidal cavity that was used in detecting ultra-weak photon emission from biological objects. The cavity can assemble the photons from biological sample at one focal plane of the rotation ellipsoidal cavity to the photomultiplier tube at another. The paper discusses the mathematical model of the cavity and the efficiency of collecting photons with the cavity. The measuring results for biological sample are given. The results are shown that the efficiency of collecting photons for the system with the cavity is evidently raised.

The profilometer for on-line and non-contact measurement of the fine optical surfaces is described in this paper, which works on the principle of the differential interferometry with coaxial interference arms. The optical part of that is isolated and easy to install on the machine tools or the measuring machineries ea. This profilometer has excellent resistance to disturbance, especially to mechanical vibration, when the amplitude of vibration is about 300nm. So it still can be used to measure the micro-profile with sub-nanometer resolution. The vertical resolution of the profilometer is better than 0.05 nm rms. and need not add any condition or pretreatment

With the development of the optical technology, wavelength division multiplexing (WDM) is becoming an important technology for the enhancement of bandwidths of fiber-optical networks. Bragg gratings utilize the fact that light is diffracted from a grating only if the Bragg condition is fulfilled. In the paper a new kind of measure called directly layered multiple VBGs (volume Bragg gratings) is presented, which is fabricated by photorefractive volume holographic technology, and the multiple VBGs fabricated by this method with layered structure is more compact, the corresponding system could, more sufficiently, utilize the volume of photorefractive lithium niobate crystal. In our experiment the VBGs can be formed by illumination of interference field of two thin sheet beams expanded and collimated through two cylindrical lenses, and then multiple VBGs can be accomplished at the same location by angle-multiplexing technique. And then the layered structure can be formed by space-multiplexing holographic technique, i.e. after the fabrication of the previous layer, the following layer is able to be created by above multiple illuminations through moving crystal along the sheet beam normal with a certain space. The steady layered multiple VBGs in LiNbO₃:Fe crystal can be achieved through thermal fixing technique. Several layered structures are fabricated, that are respectively composed of four superimposed VBGs in LiNbO₃ crystal. The spectrum distribution of each layer gratings transmittance was measured by utilizing Ando AQ6317C optical spectrum analyzer

A new sensing unit structure of the uncooled infrared detector based on the multilayer lithium tantalite (LiTaO3) pyroelectric functional thin film is introduced in this paper. An innovative sol-gel process using lithium acetate and tantalum ethoxide as starting materials to prepare the multi-layer LiTaO₃ functional thin film on two different substrates is described in detail. The glacial acetic acid addition in the tantalate ethoxide sol results in a new type molecularly modified precursor. And the LiTaO3 thin film was fabricated by spinning coater at 3000 r.p.m. To prevent the coatings from cracking, two-step "slow preannealing" was used to thermally treat the LiTaO₃ thin film samples. The gold black infrared absorbing layer of the LiTaO₃ thin film sample was evaporated about 300 nm in a clean evaporating chamber charged with nitrogen gas under a pressure of about150 Pa. The voltage response of the LiTaO₃ thin film sample was obtained by the infrared device measurement system. The specific detectivity peak of the LiTaO₃ thin film sample is near 6.1×10⁸cmHz^1/2W^-1 from 1Hz to 100Hz.

Defects in thin film are the most important factors resulting in laser-induced damage of far-infrared laser thin film components, and always a major concern. The defect is a primary problem for infrared thin film of 3.8um in some optical systems. In this paper, single layer of ZnS YbF3 and multilayer coating is produced by thermal evaporation, and species, properties and derivation of defects in these thin films are introduced firstly, Then, the influence of material and evaporation rate on the surface defect density of laser thin film is analyzed. Finally, this paper put forward the appropriate deposition rates of thin film. The result shows that the nodule and concave hole defects are the mainly in the infrared thin film of 3.8um, and YbF3 has a great effect on the defect density in thin film. Also, the deposition rate of YbF3 has a large effect on the number and area of particles deposited on the substrate, as the evaporation rate increases, the number of particles increases markedly. It is possible that the spitting change of fused deposition material increases when the rate increases, since the centre temperature of fused deposition material increases. The defect density from 7.3X10^-3 reduces to 6.8X10^-4 through reducing the rate. Finally, the authors found it was appropriate when deposition rates were 4Å/s for ZnS and 2Å/s for YbF3, respectively.

In this paper we analyze the change of polarization state for a laser optical system which includes a Cassegrain beam expander and several fold mirrors. First, this system operates over a broad spectral band and is with several separated wavelengths, therefore, strong polarization effects will occur at certain waveband. The polarization state changes of different wavelengths at the exit pupil are discussed mainly based on the comparison of their Point Spread Function (PSF) and Strehl Ratio respectively. Then, fold mirrors cause large angles of incidence and can rotate in azimuth and zenith. The amplitude diattenuation and retardance are calculated at different azimuth and zenith of the beam director assembly. In this paper, Code-V commercial optical-engineering software is used to model the polarization behavior for the system. The factors mentioned above, which are spectral bandwidth, angle of incidence of surfaces and systemic coatings, are taken into consideration in the process of simulation. The result of the study shows that the polarization properties at certain wavelength are satisfactory except some other wavelengths are not. This laser system is more sensitive to retardance than to diattenuation. It is concluded that polarization is an important factor that affects the performances of the whole system and the design of laser optical system should take into account the polarization effects.

By using the Gaussian light beam approximation and from the viewpoint of mode matching, the optical coupling theory between single mode fiber and optical antenna, which is based on the matrix optical theory and the ABCD law, is employed to present a universal designing method for transmitting optical antenna of a terrestrial line-sight optical communication system .The physical meaning and choosing method with its relative parameter are also discussed in detail, and an experimental example of the transmitting optical antenna for a terrestrial line-sight optical communication system is given as well. Through the testing of the designed transmitting optical antenna with the help of a laser light beam analysis instrument, the incident Gaussian light beam waist spot radius is 4.7μm, while the divergence angles of the transmitting Gaussian light beam in the two perpendicular directions are 1.9mrad and 1.5mrad, respectively, which can almost agree with the parameters of the designing theory above. In the end, the possibility of improving the quality of transmitting optical antenna and the reliability of space optical communication through applying technologies such as converting the elliptical Gaussian light beam into the round Gaussian light beam, the plane coupling into the spherical coupling and film-plating the optical antenna etc is discussed.

An optical system for free space optical communication is designed, which are composed of three parts: Optical sender are designed as Schmidt-Cassegrain antenna to collimate the laser beam. λ/2 plate and polarization beam splitter are used to decrease the interference of astigmatism and reflection. The dense-lines Fresnel lens as an optical receiver, and further an automatic tracking system is employed to eliminate the pointing error between communication terminals. Experiment shows that the laser divergence of 2 mrad is obtained for the communication system at the wavelength of 850nm, with pointing error less than 5 μ rad, and laser power of 10dB. The detector can receive -17.5dB even in middle fog condition 2 km ranged. The system can be used for free space optical communication in 2km distance except under especial atrocious weather.

A simple method of broadband distributed Raman amplifier is presented based on Chirped Fiber Bragg Grating Filter. C+L band gain flattened distributed fiber Raman amplifier with bandwidth of 50nm (1520nm~1570nm) and 15 dB averaged gain and ± 0.6dB gain ripple using single pump has been demonstrated. Compared to design methods of other existing Raman amplifier, our method has a substantial improvement in simplifying system.

In this work, we reported the fabrication and characterization of an Al_xGa_1-xN /GaN hetero-epitaxial front-illuminated visible-blind UV photodetector with very high external quantum efficiency. This device was grown on one side of polished sapphire substrate using a low-temperature AlN buffer layer created by three-pocket multi-wafer system metalorganic chemical vapor deposition (MOCVD) with a vertical reactor. This device consisted of a 2.5μm thick GaN n-layer, a 0.4μm thick GaN i-layer and Al_0.1Ga_0.9N "window layer", followed by a 10 nm GaN:Mg p+ contact layer. In order to investigate the effect of p- Al_0.1Ga_0.9N thickness on the characteristics of the photodetector, three samples only with different p-AlGaN thicknesses of 0.1μm and 0.15μm were fabricated. All of the device processing was completed using standard semiconductor processing techniques that included photolithography, metallization and etching. Compared the results of these three samples, the sample with 0.15μm thick p-AlGaN possesses the highest quantum efficiency and its zero-bias peak responsivity was found around 0.20A/W at 365 nm, corresponding to an external quantum efficiency of 85.6%. Moreover, this device exhibits a low dark current density of 3.16nA/cm² at zero-bias.

Detection of fluorescent microarray slides can be divided into two categories: one is confocal scanning detection in which a photomultiplier tube is used as fluorescence sensor, and the other is flood illumination of the entire microarray slides and uses a Peltier cooled CCD as fluorescence sensor. CCD can afford high quantum efficiency, simultaneous illumination and detection of multiple pixels, and easy mechanical design, but its dynamic range and sensitivity are not as good as those of photomultiplier tube. At the same time, the Peltier cooled CCD camera is much more expensive than a high performance photomultiplier tube. Confocal scanning provides high dynamic range, good sensitivity and high signal-to-noise ratio, but the system design is difficult when considering rapid scanning speed, high resolution and large numerical aperture. There are three typical confocal scanning apparatuses which are mechanical scanning, optical scanning and optical-mechanical scanning. Their scanning mechanism, advantage and disadvantage are analyzed respectively. With the former understanding, a new optical-mechanical scanning apparatus is described in detail. It employs two lasers to excite the Cy3 and Cy5 fluorophores on the microarray slides. The emitted fluorescent signal is detected using a photomultiplier tube sequentially. One dimension scanning of the slides is performed by a telecentric f-θ objective with a moving coil optical scanner; the other dimension is scanned through a stepping motor driving a precision guidance. This apparatus is low-noise, economical and fast in scanning speed.

Effects of residual stresses on mechanical properties such as voltage vs. displacement response, pull-in voltage and structural resonant frequency of segmented micro deformable mirrors were investigated with both finite element method (FEM) and analytical method. A simplified model was adopted to study the structural spring constant on the existence of residual stress and two methods for imposing residual stress on structures were utilized for the purpose. Both results of analytical method and FEM show that larger structural spring constant can be obtained by introducing tensile residual stress. Consequently, mechanical properties relevant to spring constant are also greatly affected. The higher the tensile residual stress is, the stronger the structural stiffness will be. That means in order to induce the same structural displacement of mirror plate as stress-free state, higher voltage is demanded. Meanwhile, with higher tensile residual stress, larger pull-in voltage and greater structural resonant frequency are achieved. For the situation of compressive residual stress, totally the opposite influences can be observed. In conclusion, residual stress (no matter tensile or compressive) can greatly affect the mechanical properties of segmented micro deformable mirrors. Accurate control of it is needed for optimizing the structural design and improving the performance of devices.

This paper presented a bicubic uniform B-spline wavefront fitting technology to figure out the analytical expression for object wavefront used in Computer-Generated Holograms (CGHs). In many cases, to decrease the difficulty of optical processing, off-axis CGHs rather than complex aspherical surface elements are used in modern advanced military optical systems. In order to design and fabricate off-axis CGH, we have to fit out the analytical expression for object wavefront. Zernike Polynomial is competent for fitting wavefront of centrosymmetric optical systems, but not for axisymmetrical optical systems. Although adopting high-degree polynomials fitting method would achieve higher fitting precision in all fitting nodes, the greatest shortcoming of this method is that any departure from the fitting nodes would result in great fitting error, which is so-called pulsation phenomenon. Furthermore, high-degree polynomials fitting method would increase the calculation time in coding computer-generated hologram and solving basic equation. Basing on the basis function of cubic uniform B-spline and the character mesh of bicubic uniform B-spline wavefront, bicubic uniform B-spline wavefront are described as the product of a series of matrices. Employing standard MATLAB routines, four kinds of different analytical expressions for object wavefront are fitted out by bicubic uniform B-spline as well as high-degree polynomials. Calculation results indicate that, compared with high-degree polynomials, bicubic uniform B-spline is a more competitive method to fit out the analytical expression for object wavefront used in off-axis CGH, for its higher fitting precision and C² continuity.

Metallic mesh has been widely used in electromagnetic interference windows. While the duty ratio of curved mesh equals to planar mesh', the theory of planar mesh may be applied to curved mesh according to equivalent-circuit model. So the idea that latitude lines intersect latitude lines to form isometric mesh on the concave of a sphere is put forward, and the method of fabricating the mesh by concentric optical scan is introduced. The movement parts of equipment consist of an erection turning, a horizontal dividing and a pitching dividing spindle. Firstly, a spherical substrate is fixed on the horizontal dividing spindle that has been set horizontally on the erect turning spindle, the substrate revolves around the axis of the erect spindle, the tube of object lens that is fixed on the pitching dividing spindle steps at pitching direction, and a revolving circuit of the substrate corresponds to a step of the tube. Gradually, a set of latitude lines is attained. Afterward, the substrate makes a quarter turn around the horizontal spindle, another orientation latitude lines are also gained. Thus, the isometric mesh on the concave of a spherical substrate is gained. The process comprises surface cleaning, coating photoresist, laser direct writing, development, evaporated film, dissolving photoresist and plating. The fabricated spherical mesh has a line width of 7μm and a period of 600μm. Experiment shows that infrared transmission and electromagnetism shield efficiency of the metallic mesh are relatively consistent with theoretical value.

Schmidt system is a famous optical system. The corrector equation based on the third-order aberration theory has been acknowledged all along. When the previous equation is confirmed in characteristic of the aspheric surface equation and optical design program ZEMAX, it is found that the equation of the corrector has some errors. Analyses of this problem are given. A new corrector equation is established. The new equation is confirmed seriously by the optical design program ZEMAX again, it can be deduced that the coefficient α=1/2r₀₂, and the spherical aberration coefficient ΣS₁=0. This improvement is very useful for the optical design of Schmidt system, which quickens the optimization and easily reaches the optimal design data.

CCD noises and their causes are analyzed. Methods to control these noises, such as Correlated Double Sampling (CDS), filtering, cooling, clamping, and calibration are proposed. To improve CCD sensor's performances, the IC, called Analog Front End (AFE), integration of CDS, clamping, Programmable Gain Amplifier (PGA), offset, and ADC, which can fulfill the CDS and analog-to-digital conversion, is employed to process the output signal of CCD. Based on the noise control approaches, the idea of chip design of linear CCD drive pulse generator and control interface is introduced. The chip designed is playing the role of (1) drive pulse generator, for both CCD and AFE, and (2) interface, helping to analysis and transfer control command and status information between MCU controller and drive pulse generator, or between global control unit in the chip and CCD/AFE. There are 6 function blocks in the chip designed, such as clock generator for CCD and AFE, MCU interface, AFE serial interface, output interface, CCD antiblooming parameter register and global control logic unit. These functions are implemented in a CPLD chip, Xilinx XC2C256-6-VQ100, with 20MHz pixel frequency, and 16-bit high resolution. This chip with the AFE can eliminate CCD noise largely and improve the SNR of CCD camera. At last, the design result is presented.

Since Deb's experiment in 1973 on the electrochromic effect, transmissive electrochromic devices (ECDs) exhibit outstanding potential as energy efficient window controls which allow dynamic control of the solar energy transmission^[1]. These devices with non-volatile memory, once in the coloured state, remain in the same state even after removal of the field. The optical and electrochemical properties of electrochromic windows using magnetron sputter deposition tungsten oxide thin films and titanium oxide doped tungsten oxide thin films are investigated. From the UV region of the transmittance spectra, the band gap energy from the fundamental absorption edge can be determined. And the impedance of these thin films in 1 mol LiClO₄ propylene carbonate electrolyte (LIPC) are measured and analysed. Equivalent circuit of thin film impedances, and correlative resistances and constant phase angle element are gained. SEM and XRD of the tungsten oxide thin films and (1-x) WO₃xTiO₂ thin films are studied. These performance characteristics make tungsten oxide thin films and titanium oxide doped tungsten oxide thin films materials suitable for electrochromic windows applications.

In the field of microelectromechanical systems, a challenge to MEMS designers is to create low-order dynamic device models that can accurately capture the complex behaviors which may be discovered only through experiments or full three-dimensional simulations. Computer aided design (CAD) tools allow modeling and simulation of devices that may not have been constructed yet, but now only few softwares are available for modeling and analysis of microsystems. In this paper, we attempt to use MEMSPRO and ANSYS to fulfill the modeling and simulation of silicon micromechanical electrostatic comb drive resonators. A 3D model is constructed. Then the model is analyzed by a finite element analysis tool, ANSYS. We implement the static responses and harmonic responses of the model so that the static and dynamic characteristics of the resonator can be obtained to help improve design quality and efficiency. Based on the analysis results, low-order dynamic device model of the resonator can be tuned and further optimized. The effectiveness of the CAD/CAE technology in the development of MEMS is demonstrated in the paper.

Reactive magnetron sputtering can be used to prepare graded index coatings. In this paper the relationship between the refractive index of the coatings and the partial pressure of reactive gas is discussed by experiment, in which A, O₂ and Si are taken as sputtering gas, reactive gas and target material separately. And we have come to such conclusions that with the increase of partial pressure of reactive gas the color of the coatings turns shoal, the transmittance minimum of the coatings increases and the refractive index of coatings decreases according to the fitting rule of cubic polynomial. From XRD analysis, it can be seen that the coatings are identified to be amorphous.

In an adaptive-optical (AO) system, the wavefront of optical beam can be corrected with deformable mirror (DM). Based on MicroElectroMechanical System (MEMS) technology, segmented micro deformable mirrors can be built with denser actuator spacing than continuous face-sheet designs and have been widely researched. But the influence of the segment structure has not been thoroughly discussed until now. In this paper, the design, performance and fabrication of several micromachined, segmented deformable mirror for AO were investigated. The wavefront distorted by atmospheric turbulence was simulated in the frame of Kolmogorov turbulence model. Position function was used to describe the surfaces of the micro deformable mirrors in working state. The performances of deformable mirrors featuring square, brick, hexagonal and ring segment structures were evaluated in criteria of phase fitting error, the Strehl ratio after wavefront correction and the design considerations. Then the micro fabrication process and mask layout were designed and the fabrication of micro deformable mirrors was implemented. The results show that the micro deformable mirror with ring segments performs the best, but it is very difficult in terms of layout design. The micro deformable mirrors with square and brick segments are easy to design, but their performances are not good. The micro deformable mirror with hexagonal segments has not only good performance in terms of phase fitting error, the Strehl ratio and actuation voltage, but also no overwhelming difficulty in layout design.

Double layer films of SiO₂/Si₃N₄ were prepared on sapphire (α-Al₂O₃) by radio frequency magnetron reactive sputtering in order to increase the transmission of infrared windows of sapphire. Composition and structure of each layer of the film were analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The refractive index of deposited films was measured and effects of the coatings on optical properties of sapphire have been studied. Transmittance spectrum of uncoated sapphire and the sapphire coated on both sides with double layer films of SiO₂/Si₃N₄ have been measured using a Fourier Transform Infrared (FTIR) spectrometer. The results show that the designed SiO₂/Si₃N₄ films can increase the transmission of sapphire in mid-wave infrared greatly. The average transmittance of sapphire coated with the double layer films of SiO₂/Si₃N₄ on both sides, at wavelengths from 3 to 4.5um, can be increased to 96.3%, 10.9% higher than uncoated sapphire sample with 85.4% in average transmittance at room temperature. What's more, sapphire uncoated and coated on both sides with double layer films of SiO₂/Si₃N₄ were heated to 1000^oC and the transmissions at high temperature were measured. The results show that the transmission of coated sapphires was higher than that of uncoated ones at high temperature. The decreases in average transmission were less than 2% for the sapphire coated with the designed double layer films at 1000^oC.