Light-emitting diodes(LEDs) have become very attractive in different application field such as Solid State Lighting, automotive and street lights, due to their long operative lifetime, lower energy consumption etc. This paper mainly introduces the accelerated aging test, we focus our attention on the study of a life model for LEDs by relating the time to failure with the supplying condition. The constant accelerated aging experiments were firstly performed on LED samples. Process the experiment data by exploiting the degradation of LED optical power formula and degradation coefficient. Finally, the average lifetime of the samples under normal conditions was calculated via using numerical analytical method. According to data, analysis the test result and the failure mechanism of LED, provide the technical basis to improve product design and quality assurance.

Mini-projectors based on LED illumination have already become a hotspot of projector industry, and time-sequential stereoscopic mini-projector has been developed. However, viewers to this type of 3D projector usually suffered from dark and flickering images caused by false synchronization of images and glasses, and the low transmittance of LC glasses. We propose a new type of polarized mini-3D-projector, which employs double LED illumination engines, and double LCoS panels. The optical model of the optical engine for the mini-3D-projector is built based on the measured optical qualities of the key optical elements. The large divergence angle is the main factor which affects disparity according to the simulated analysis. The first version of prototype is developed, which has low disparity (<5%) and performs comfortable viewing experience. This new type of 3D mini-projector has the advantages of the both conventional 3D projection technologies.

The Eu²⁺ and Dy³⁺ co-doped luminescence high silica glass was prepared by combining porous glass preparation and sintering process. The emission spectra and excitation spectra of luminescence glasses were measured. With the excitation of ultraviolet (UV) wavelength of 365nm, there were two emission bands with central wavelength 480nm and 573nm in spectra of samples which presented the near white light luminescence. The energy transfer process from Dy³⁺ to Eu²⁺ and concentration quench process of Eu²⁺ in samples were demonstrated by comparing the relative spectral intensity of emission spectra and excitation spectra. This type of glass might be an adoptable candidate for white LED through an appropriate UV chip excitation.

Frequency filtering, high pass filtering pro-process method, Laplace differential template, finite impulse response filtering, and wavelet transform have been proposed for eliminating zero-order diffraction in digital hologram reconstruction. The characteristics and limitations of these methods are summed up in this paper after systematically analyzing those. Furthermore, through comparing the quality of reconstructed images with or without a mean filter, it shows that the contrast and resolution have significantly been enhanced with mean filter. Finally, an effective method of improving the quality of reconstructed image, which combines wavelet transform with mean filter, is presented by contrasting and analyzing the experiment results.

A multiple height-transfer interferometric technique was developed to increase the absolute distance measurement capability of a metrology system that uses a tunable laser. Using multiple accurately calibrated reference heights, this technique relaxes the requirement of knowing accurate wavelength information for multiple wavelength interferometry while maintaining its advantages. We present an uncertainty analysis, analyze the primary sources of uncertainties limiting the performance of this technique and discuss how errors can be minimized. Measurement results of 3D-images obtained from a variety of objects are presented. The measurement uncertainty is experimentally demonstrated to be smaller than 0.2 μm over 50 mm for two discontinuous surfaces.

An encoding algorithm is proposed for three-dimensional (3-D) information using optical asymmetric cryptosystem and the digital interferometry. 3-D information can be treated as an ensemble composed of multiple points, and every point spreads in a spatial limited field. Due to the free space coordinates, the encryption system of 3-D information can be regarded as an optical asymmetric cryptosystem. We encrypt 3-D information with the double random phase-truncated encoding, and then record the amplitude of ciphertext by digital interferometry. Computer simulations demonstrate the feasibility and effective of the proposed method. This cryptosystem is also numerically tested with the incorrect keys, the addition noise to the ciphertext, and spatial information occluded ciphertext. The proposed algorithm has three advantages: the high efficiency of encryption, the safety provided by one added dimension, the increasing information quantity and the optical asymmetric cryptosystems. The high robustness to the system is also achieved.

We propose an efficient calculation method to display three-dimensional information with purephase computer-generated holograms (CGHs). The object composed of points is conventionally divided into a set of planar segments vertically along with the axis. In this way, the number of planar segments is less than the number of points, which means that the total number of diffractions needed to calculate decreases. However, it is low efficient, for sometimes one planar segment only contains one point. We propose to quantize the locations of planar segments to solve this problem. The simplest way to quantize locations is to divide the object into the equal interval planar segments parallel with each other in the axis. The points out of these planar segments are projected to their nearest segments. Compared to traditional CGHs, the proposed method dramatically reduces the computing cost. Both simulations and experiments demonstrate the feasibility of the location quantization algorithm.

Uniform illumination plays an important role in Digital Speckle Pattern Interferometry (DSPI) of measuring a large object. This paper presents a method that by designing a specified DOE with certain algorithm in front of laser diodes, a large and uniform illumination could be achieved at the designed distance. The fluctuation of no more than 10% has been analyzed for its influence on interferogram. Only 6 semiconductor lasers are necessary in the interferometer to lighting its view in theory and the experiment with the simulated illumination has been done. The fringes of deformation at different parts of the object show that this method is suitable for large area detection.

We present a new and robust method for determining in-plane displacements of an object from distorted Digital Speckle Photography (DSP) images. This new approach is designed particularly to facilitate accurate measurement of deformations of steel samples during a gas quenching heat treatment process, where rigid body motion and large deformations lead to unwanted image distortions. The new method allows the computation and correction of image rotation and magnification via Radon and Fourier-Mellin Transformations prior to calculations of in-plane displacements, thereby alleviating the inaccuracy that arises from the cross correlation of distorted images in conventional DSP. The method is validated through simulation and measurements with predefined deformations. Initial studies show that the new method is well suited for this application and that it enables measurement of displacements with high accuracy in the micrometer range.

The nanometer-level precise phase-shift system is designed to realize the phase-shift interferometry in electronic speckle shearography pattern interferometry. The PZT is used as driving component of phase-shift system and translation component of flexure hinge is developed to realize micro displacement of non-friction and non-clearance. Closed-loop control system is designed for high-precision micro displacement, in which embedded digital control system is developed for completing control algorithm and capacitive sensor is used as feedback part for measuring micro displacement in real time. Dynamic model and control model of the nanometer-level precise phase-shift system is analyzed, and high-precision micro displacement is realized with digital PID control algorithm on this basis. It is proved with experiments that the location precision of the precise phase-shift system to step signal of displacement is less than 2nm and the location precision to continuous signal of displacement is less than 5nm, which is satisfied with the request of the electronic speckle shearography and phase-shift pattern interferometry. The stripe images of four-step phase-shift interferometry and the final phase distributed image correlated with distortion of objects are listed in this paper to prove the validity of nanometer-level precise phase-shift system.

Due to its uniform dispersion and higher diffraction efficiency, transmission volume phase holographic grating (VPHG) has been widely used for astronomical spectroscopy, ultrafast lasers compressors and wavelength division multiplexers. According to its application requirement and based on the Rigorous Coupled Wave Analysis (RCWA), a transmission VPHG with a frequency of 196lp/mm is designed and manufactured in this paper. The thickness of gelatin and the modulation of refraction index are optimized for high diffraction efficiency over a wavelength range from 420nm to 1000nm. The grating was recorded in dichromate gelatin (DCG) and in a symmetrical light path. By controlling the coating, exposure and post-processing conditions, the thickness of gelatin and the modulation of refraction index can be adjusted. The diffraction efficiency varied within the required wave band and the polarization property of the illumination wave were measured and compared with that of the theoretical ones. From the results, it can be seen that by adjusting and controlling the preparation conditions of DCG plates, the exposure value and post-processing technique, the peak diffraction efficiency of VPHG reaches to 47% and the average diffraction efficiency is above 35% in the spectral coverage, which is close to the theoretical values. This transmission VPHG can be applied in a prism-grating-prism (PGP) imaging spectrometer.

In this paper, a novel method for holographic projection is presented. SLMs are employed to modulate incident light beams and reconstruct the output image by interference. There is a great advantage of this novel method that the algorithm for calculation the phase patterns on SLMs does not need iterative process, which is greatly computationally efficient and hence provides a possibility to achieve real-time video holographic projection based on standard PC hardware. Two holographic-projection architectures for this novel method are proposed. Simulation results demonstrate the validity of this new proposed method. It is believed that this technique is useful in further real-time video holographic projection.

A new method based on the combination of Finite-Difference Time-Domain (FDTD) algorithm and Fourier transform was proposed to analyze the Fraunhofer vector diffraction of gratings in this paper. The interaction of a grating with the incident linearly polarized light was simulated using FDTD algorithm, the complex amplitude distribution on the rear plane of the grating was extracted, and then the Fraunhofer diffraction pattern was obtained by performing Fourier transform of the complex amplitude. It was found that for the rectangular phase grating if the period of the grating is comparable to the wavelength of the incident wave, the propagation speeds of the TE and TM waves in the dielectric of the grating are different, which makes the diffraction of the grating is polarization dependent. Besides, the relative phase retardations of TE and TM waves formed on the rear plane of the grating are different and both of them can be controlled by changing the thickness of the grating, which makes it be realized that the intensities of TE and TM waves concentrate onto the 0th order and 1st order separately by selecting a suitable grating thickness. Therefore a polarization beam splitter based on a rectangular dielectric grating can be easily designed.

The surface roughness of a large-size super-smooth mirror is studied by grazing incidence X-ray scattering method (GIXRS). We derive the two-dimensional theoretical model based on Tong's result in 1993; In light of our formulae, the power spectrum density (PSD) of a mirror surface can be correlated to the intensity distribution of X-ray scattering. A 210mm-long mirror is measured at the beamline 16B at Shanghai Synchrotron Radiation Facility (SSRF) and the data is analyzed. The result indicates that the root mean square (RMS) of the surface roughness calculated by our formulae is in good agreement with that measured by a white-light 3D profiler.

In this paper, a novel in-situ surface measuring technique for optical elements with aspheric surface is presented. It is a contact type probe, and can be used for measuring ground surfaces. The theory of this technique develops from coordinate measuring machine (CMM), and the measurement accuracy of this technique is depended on the accuracy of computer numerical controlled (CNC). By installing a special equipment with high accuracy measuring head in main spindle of CNC machine, and moving the probe along the path which is described by a mathematical aspheric expression precisely, we could get relative errors of sag height of any position in this path. With this technique, the repeat positioning error caused by traditional off-line measurement will be avoided. The author also has finished a special software with VC++ 6.0. With this software, the form error of ground work piece could be corrected rapidly. This software can calculate and handle the arrangement automatically with all parameters which are required to input in operation interface. In the correction stage, the software can analyze and process error data and generate a new NC program with corrected data for next grinding stage. After 2 or 3 times measuring and correction, the surface shape error of the aspheric optical element will be less than 1μm. The finished work piece has a very good surface finish and can be polished with high quality.

We present a novel method to calibrate fiber optical tweezers. This paper proposed a new calibrating method solving the problem, which makes the calibration for fiber optical tweezers in a wide range of output optical field possibly. Based on electromagnetic field momentum conservation law and finite-difference time-domain method, we calculated and analyzed the force of multiple particles are simultaneously trapped, and get the f-x (trapping fore-distance from the fiber tip) curve, which is consistent to the experimental results. Theoretical and experimental results show that the fiber optical tweezers is more conducive to study the precise mechanical properties of biological cells in a larger range.

The positions and orientations of the tool and workpiece are analyzed for machining axisymmetric aspheric convex surface and the position and orientation matrixes of the workpiece and the tool are obtained. The relationship between the tool and the workpiece is set up by using the method of coordinate transformation. The basic modules and the necessary motions for generating axisymmetric aspheric convex surface are clarified. And the possible structural configurations of the machine tool are proposed and optimized. The results in this paper facilitate the innovation design of a machine tool for generating axisymmetric aspheric convex surface.

In this paper, we study the regular and flexible microstructured silicon theoretically using the Rigorous Coupled Wave Analysis and Finite Difference Time Domain methods. We calculate the reflective spectra of the conical structures of three different sizes by using the multi-step approximation. The calculated results show that the smallest 0.5μm structures have the lowest reflectance. The angle dependence of the reflectance of microstructured silicon is also talked about. Then the Finite Difference Time Domain method is used to simulate the absorptance of the regular and flexible microstructured silicon of three different sizes. The simulated results show that the absorptance of flexible microstructured silicon is a little lower than that of the regular microstructured silicon. At last, The absorption spectrum of the flexible surface microstructured silicon is as high as 97% in the visible and insensitive to the change of the incident angle of the light. The calculated results are verified by the measured spectra.

In order to develop the near- field optical tweezers with perfect function , We design the near-field optical fiber optical tweezers basing on the multi-core of the optical fiber. Combining the total internal reflection and multi-core optical fiber, we form evanescent wave on the fiber water interface forming , and realize the capture of object .It can separate the near-field optical tweezers and its control from the microscopic observation system effectively, so It enhance the operability of near-field optical tweezers and the ability of active capture greatly. The Multi-core optical fiber constitutes the Near-field optical tweezers, the superposition of the coherent light from opposite transmission forms a area of capture. Interference effect makes light intensely, at the same time the capture space becomes more and more narrow. They can improve the capture function of the new generation of all-fiber near-field optical tweezers greatly. And we quantitatively calculating the optical trap force of the micron-grade particle. In this passage, there is a new progress in setting up the near field optical tweezers' model and the calculation method. Moreover, it improves the using value of the near field optical tweezers technology in the life sciences.

Hexagonal Boron Nitride (h-BN) films For high-frequency SAW devices were deposited on Ti/Al/Si(111) wafers by RF magnetron sputtering. The structure of h-BN films was investigated by fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectra. And the surface morphology and piezoelectric properties of h-BN film was characterized by atomic force microscopy (AFM). And the characterization results show that when the RF power is 300w and other experimental parameters were fixed, h-BN films was in high purity and the c-axis oriented, h-BN films was in high purity and the c-axis oriented, and the particles of which are uniform and compact, roughness is 2.63nm with piezoelectric and piezoelectric response even, meet the requirements of high sound propagation speed and excellent piezoelectric for high frequency SAW devices. The studies of piezoelectric test of thin films have shown that PFM test method of atomic force microscopy was suitable for characterization of piezoelectric and properties of the piezoelectric response distribution of nano-structure semiconductor thin film.

The infrared normal spectral emissivity of microstructured silicon prepared by femtosecond laser was measured for the middle infrared waveband at temperature range 200 to 400°C. Compared to that of flat silicon, emissivity was enhanced over the entire wavelength range. For a sample with different spike height, the max emissivity at a temperature of 300°C emissivity nearly reaches to 0.99 . Although the average emissivity is not very higher, it can be used stably at more wide temperature ranges. These results show the potential for microstructured silicon to be used as a flat blackbody source or silicon-based devices.

Optical delay line (ODL) implements the vertical or depth scanning of optical coherence tomography, which is the most important factor affecting the scanning resolution and speed. The spinning spiral mirror is found as an excellent optical delay device because of the high-speed and high-repetition-rate. However, it is one difficult task to machine the mirror due to the special shape and precision requirement. In this paper, the spiral mirror with titled parabolic generatrix is proposed, and the ultra-precision turning method is studied for its machining using the spiral mathematic model. Another type of ODL with the segmental shape is also introduced and machined to make rotation balance for the mass equalization when scanning. The efficiency improvement is considered in details, including the rough cutting with the 5- axis milling machine, the machining coordinates unification, and the selection of layer direction in turning. The onmachine measuring method based on stylus gauge is designed to analyze the shape deviation. The air bearing is used as the measuring staff and the laser interferometer sensor as the position sensor, whose repeatability accuracy is proved up to 10nm and the stable feature keeps well. With this method developed, the complex mirror with nanometric finish of 10.7nm in Ra and the form error within 1um are achieved.

The theory and application of SPH (Smoothed Particle Hydrodynamics) is presented. A Langrangian SPH model is conducted using the LS-DYNA software. As a recently developed and promising method, particles are used in SPH as a substitute for mesh and large material deformation is easily handled. Material separation is well achieved through defining nodes to surface contact. The cutting process of 4340 steel is simulated with SPH method. The process of chip formation is depicted well through the natural flow of SPH particles. The stress distribution and changes of cutting force displays the constitutive behavior of material during cutting. And the maximum value of Von Mises stress, shear stress and plastic strain are concentrated at primary deformation zone, especially near the tool tip.

A special designed fiber with double layers of cores was investigated theoretically and experimentally. This fiber is widely used in astronomy to transform light from the telescope to the optical spectrum analyzer. The refractive index profile of this fiber was measured firstly. The testing result showed that the fiber has three layers of refractive index. A special layer of the highest refractive index is between the uniform general fiber core and the general low-refractive-index fiber cladding. This highest layer has higher local numeric aperture (NA), which can absorb more light when the incidence angle is little larger. A series of experiments have been done to prove that the NA is larger than normal fibers due to the higher-index layer. Two special incidence angles were measured respect to uniform and circle mode pattern.

We design a new kind of high birefringence photonic crystal fibers with square-lattice cladding. Through changing the size of only four air holes in the x and y direction respectively, the birefringence is highly increased. It reaches to 1.643×10^-3 when the wavelength is 1.8μm. Based on the finite element method, the mode fields, dispersion and confinement loss of this kind of photonic crystal fibers are all analyzed.

Grating light modulators are the key wavelength scanning devices for a MOEMS spectrometer. In this paper, we build a vectorial diffraction model of grating light modulators theoretically based on Finite Beam Rigorous Coupled Wave Analysis theory. Then we calculate the diffraction efficiency of grating light modulators at the spectral range from 900nm to 1700nm. The numerical spectra indicate that the grating light modulators can realize wavelength scanning by changing the distance between the upper and the bottom layers. The grating light modulator can act as a programmable pixilated optical switch with high contrast. The diffraction efficiency is stable when the θ changes from -10 degrees to 10 degrees and the Φ changes from -30 degrees to 30 degrees. The effects of the bandwidth on the diffraction efficiency of the grating light modulators can be ignored. The average on state diffraction efficiency is 0.83 and the average off state diffraction efficiency is 0.05 when the grating light modulators chip has 256 pixels. The experimental results show that the vectorial diffraction model is more efficient than the scalar diffraction model.

GaAs/In_xGa_1-xAs/GaAs double-heterostructure nanowires were grown by Metal-organic Chemical Vapor Deposition on GaAs (1 1 1)B substrate using the vapor-liquid-solid growth method. By tuning the In content(x) from 0.2 to 1, we fabricated several GaAs/In_xGa_1-xAs/GaAs nanowire heterostructrues with different In_xGa_1-xAs parts and studied their characteristics. We found that all the InGaAs segments were successfully grown on GaAs sections, while the InAs nanowires were grown kinked or downward. By inserting a composition-graded In_xGa_1-xAs buffer segment between GaAs and InAs nanowires, high yield of straight GaAs/In_xGa_1-xAs/GaAs nanowire heterostructrues were realized.

The spin-exchange relaxation free (SERF) magnetometers are the most sensitive atomic magnetometers, the optimum sensitivity of which is on the order of 0.1 fTHz^-1/2. The size of the vapor cell is important in the miniaturization of the Cs vapor magnetometer, for it determining other components'. The more importance is dependence of the spin-destruction rate, which is the maximum relaxation rate in the SERF regime. This paper presents the design of the vapor cell at Cs SERF magnetometers and the discussion of the highest sensitivity achieved in different sizes.

The spatial effect of the interference of electromagnetic wave packet has been analyzed for the film structure considering the spatial separation among the multiple reflections. The reflected intensity of polarized electromagnetic wave packet is different considering with and without spatial separation effect. There is significant difference occurred between the situations of the interference with or without consideration of the spatial effect. When the phase delay δ = nπ (n∈1-6). It will be reasonable to obtain the reflected intensity by neglecting the spatial separation only for the thinner film with the thickness much smaller than the wavelength accompanied with the condition to satisfy that δ < π, otherwise, the intensity equation used for the periodic or non-periodic structures will be modified by including the spatial separation in the data analysis and applications.

The characteristics of the polarization coupling of two optical micro/nano-fibers (MNFs), which are placed close and parallel each other, were investigated by three dimension full vector beam propagation method (3-D FVBPM). The analytical results of the polarization coupling show that a polarization beam splitter (PBS) device can be constructed based on the coupling of two parallel and close MNFs. In order to optimize the polarization splitting performance of the device, the geometric parameters of the PBS, such as the diameter of optical MNFs and the gap between them were investigated through numerical stimulation. The optimal parameters are diameter of 0.9 μm, gap of 0.5 μm and length of approximately 218 μm respectively. Additionally, fabrication tolerances of each parameter for the polarization splitter PBS were also investigated. In the case of incident wavelength at 1550 nm, and the polarization extinction ratio of both output ports of PBS larger than 15 dB, the fabrication tolerances for bandwidth and overlapping length are 10 nm and , ±10μm , whereas approximately -3nm~2nm for tolerances in the diameter and gap.

In the past several years, surface plasmon polaritons (SPPs) excitation by vector beams or vortex beams has been greatly studied, and many significant achievements have been obtained, which show wide applications in near-field optics. In the paper, we study SPPs excited by radially polarized vortex beams, and concentrate on the influence of the phase distribution of vortex beams to SPP field distribution. Based on the vector diffraction theory, the expressions for SPP fields excited by radially polarized vortex beams are derived, and the orbital angular momentum (OAM) is calculated. We numerically simulate the intensity and phase distributions of SPP fields excited by radially polarized vortex beams with different topological charges, and analyze the corresponding orbital angular momentum (OAM). The results show that by changing the topological charge, we can flexibly modulate the intensity and phase distribution, and control the OAM, which presents us with more useful applications in special fields, such as optical trapping, near-field optical devices, particles rotation, and so forth.

A high-perform and compact subwavelength binary blazed grating optical switch was designed based on TiO₂-on-SiO₂. By appropriate choice of grating parameters including thicknesses, periods, height, and fill factor, to optimize the diffraction properties, a relative high diffraction efficiency and large diffraction angle was obtained simultaneously. The diffraction efficiency of the first switching channel is about 80% with a 45° diffraction angle, and the diffraction efficiency of the second channel is around 90% with a 30° diffraction angle. The device layout is simple, feasible, one-step etch, and compatible with standard CMOS technology processing.

Refracted near-field method is a very mature and reliable method for the measure of fiber refractive index profiles. In this paper, we use refracted near-field technique and set up the experimental device to measure special optical fiber refractive index profiles. We build a simulation model which refers to air-core photonic crystal fiber based on refracted near-field method, determine the structure parameters and the relationship between refractive index profiles and light intensity distribution, calculate fiber refractive index profiles deviation caused by the special fiber structure, and give the correction method. The experimental result is modified by the above and obtains a good treatment effect.

Cr mask is applied to fabricate beam sampling gratings (BSG) used in inertial confinement fusion (ICF). There are requirements on both first-order average diffraction efficiency and uniformity diffraction efficiency of BSG, so duty cycles of Cr mask grating must be measured to analyze the diffraction performance. The special Cr mask is one kind of grating with curved fringes and differing periods. In this paper, a method which can calculate duty cycles of Cr mask by measuring the zeroth-order diffraction efficiency is introduced. Based on rigorous coupled wave analysis (RCWA) theory, this method takes curved fringes as straight, and then calculates duty cycles under certain diffraction efficiencies by using the drawing of the change of diffraction efficiencies against the change of duty cycles and periods. A duty cycle can be found at a very diffraction efficiency and period. With duty cycles obtained, average diffraction efficiency and diffraction efficiency RMS can be calculated at certain etch depth. Also an example is given.

In this paper, we demonstrate a novel kind of annular waveguide layer capillary optical fiber perform which is composed of cladding, optical waveguide layer and central air hole. On the other hand, we fabricate a capillary optical fiber with an MCVD method using an advanced graphite furnace to heat and a specially made fiber drawing tower. The cross-section drawings of the optical fiber and the refractive index distribution are shown. Accordingly, we give cross section of capillary optical fiber and refractive index distribution profile. Moreover, by combining non-stable Fourier Heat-Conduction theory with fiber drawing technology, the simplified temperature field transmission model during capillary optical fiber preform drawing is established, and the temperature field distribution equation of the perform neck-down region is deduced. Meanwhile, we obtain the relationship between the temperature distribution of the neck-down region and the speed of preform feed and the furnace temperature through the numerical simulation. The conclusion shows that the high-qualified annular waveguide layer capillary optical fiber can be gotten when the temperature field distribution of the capillary optical fiber perform neck-down region is near to steady state, which well agrees with the experiment result.

Micro crack and pits of Side-polished fiber (SPF) is polished by fine sand paper and by an arc discharge, and their effects are compared. When there is no light through SPF after polishing, we will find that using an arc discharge method is better than fine sand paper polishing method especially their images being compared. When light passes SPF after polishing, we will find that transmitted light of SPF by using an arc discharge method is less than the others. In conclusion, using an arc discharge method is obviously better than fine sand paper polishing method.

Conventional optical fiber tweezers are unsuitable for operation inside cells, due to their big-size fiber tip to realize beam focusing. In this letter, new micro-optical tweezers with no focusing are demonstrated, which only demand a uniform thin-fiber to realize 3D capture and manipulation. The fused biconical taper method is adopted to produce micro-optical tweezers with a diameter of 0.75 μm, the finite-difference time-domain (FDTD) calculation method is used in the simulation and in the discussion of trapping ability, and the possibility of using this method is confirmed with experiments. These optical tweezers have a small size, tight structure, and simple production method, and it is hoped that they will become an effective tool in cell capture and manipulation.

In this paper, a new approach has been proposed to fabricate holographic blazed grating. Firstly, a rectangular or trapezoidal grating is fabricated by the combination of photoresist ashing and reactive ion beam etching, and then blazed grating can be achieved by etching rectangular or trapezoidal grating. With this approach homogenous mask profile can be precisely controlled. The result we get by simulating the evolution of rectangular mask for ion beam milling with advanced segment motion algorithm which turns out to be similar with the experimental results. The blazed grating with a line density of 1200 lp/mm is fabricated by above method, and then the blaze angle and anti-blaze angle are measured by Scanning Electron Microscope (SEM). Obtained result shows that blazed grating has 7.1 degree blaze angle and about 22.5 degree anti-blaze angle.

Electrolytic codeposition technique was adopted in the deposition of Ni-Fe-SiC composite coating on stainless steel substrate, using nickel alloyed with iron as the binder phase with SiC as dispersed particles. The results indicated that the deposit with SiC nanoparticles was level and compact; the crystal-planes of the deposit were (111), (220) and (200). The resistivity of deposit was about 30μΩ•cm. when the Fe(wt.%) ranged from 10% to 50% in the deposit, the electrodeposit Ni-20%Fe-SiC has a strong paramagnetism effect with the smallest coercivity of 2.75×10^-2 A/m. The remanence showed a monotonic decrease with the increasing iron content in deposit. Which proved that the electroformed Ni-Fe-SiC alloy has good electromagnetic property and higher corrosion resistance (with the corrosion rate 0.17 mg/dm² per hour) than those of electroforming Ni-Fe alloy. It is a promising material in the fabrication of micro actuator.

The use of progressive addition lenses (PALs) for the correction of presbyopia has increased dramatically in recent years. These lenses are now being used as the preferred alternative to bifocal and trifocal lenses in many parts of the world. Progressive addition lenses are a kind of opthalmic lenses with freeform surface. The surface curvature of the Progressive addition lenses varies gradually from a minimum value in the upper area, to a maximum value in the lower area. Thus a PAL has a surface with three zones which have very small astigmatism: far-view zone, near-view zone, and intermediate zone. The far view zone and near view zone have relatively constant powers and connected by the intermediate zone with power varies progressively. The design and fabrication technologies of progressive addition lenses have fast progresses because of the massive development of the optical simulation software, multi-axis ultraprecision machining technologies and CNC machining technologies. The design principles of progressive addition lenses are discussed in a historic review. Several kinds of design methods are illustrated, and their advantages and disadvantages are also represented. In the current study, it is shown that the optical characteristics of the different progressive addition lenses designs are significantly different from one another. The different fabrication technologies of Progressive addition lenses are also discussed in the paper. Plastic injection molding and precision-machine turning are the common fabrication technologies for exterior PALs and Interior PALs respectively.

Due to the limited depth of focus of microscope objective, a series of images taken from different sections and directions are needed to reconstruct 3D microscopy image. In this paper, we present a novel method which utilizes piezoelectric actuator, high magnification microscopy system without mirror and single CCD to observe micro-objects and reconstruct its three-dimensional image. Inverse piezoelectric effect of piezoelectric ceramics have some superior characteristics, such as high positioning resolution, high positioning accuracy, etc. And piezoelectric actuator possess the advantage of small-size, strong-power and easy- to-integrated as well. Based on these points, we designed a 360° rotation and tilt positioning platform. In this platform, Piezoelectric actuator is employed to ensure the positioning accuracy at axis-Z direction. At the same time, Motion of 360° rotation and tilt can be controlled precisely using stepping motor controlling technology. Furthermore, finite element methods (FEM) analyze software--ANSYS is used to analyze the rigidity, stress and structure optimization of the platform. This rotation and tilt mechanical positioning platform can help the single CCD to get clear, complete-view two dimensional images. This method paves the way for three-dimensional reconstruction of micro objects. Experiments demonstrate that this 360° rotation and tilt positioning stage is structure-simple and high-accurate. It can be widely used in micro-structure observing and three-dimensional image reconstruction among mechanics, materials and biology, etc.

Thin metallic films have several potential applications in MEMS field, and one of them is used as infrared absorber. In this paper, we first build a model of metallic infrared absorption and then discuss the transmission characteristics of infrared through metal and dielectric film. For a thin film material, the maximum absorption will occur when its sheet resistance equals to the impedance of free space. In order to verify the absorption property, tungsten (W) nanofilms with different thicknesses have been deposited and their characteristics of infrared absorption were experimentally studied. The infrared absorbance of W nanofilms increased as the thickness of the films increased; more than 50% IR radiation could be absorbed by W nanofilms at the wavelength of 8-12 μm.

In this paper, the oxide compositions model (OC model) is established for discussing the chromatic aberrations of gradient refractive index rod lens. The chromatic aberration for K⁺ /Tl⁺ ion exchanges is discussed based on the OC model and the Huggins-Sun-Davis (HSD) model. Theoretical result indicates that the function value mainly depends on base glass properties and nature of exchanging ion pairs, and hardly depends on the quantity of ion exchanging. Experimental results show that the chromatic aberrations using the OC model have smaller errors than them using the HSD model. The estimating average error between the OC model and the HSD model is -0.051 for the K⁺ /Tl⁺ ion exchanges.

Coupling efficiency equation of optical coherence tomography system with gradient refractive index rod lens is established and discussed theoretically and experimentally. The experimental result is consistent with the theoretical result. The higher coupling efficiency of optical coherence tomography system can be obtained if the θ which is the angle between mirror and y axis should be smaller than 0.5 degree.