bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Optical Property of Fabricating Free-Form Micro-Optical Element by Varying Dose Exposure Method
Authors: Sun Yan Jun , Leng Yan Bing , Chen Zhe , Dong Lian He
Published: May 2013

Free-form lens is a special element with non-rotating body and aspheric structure. The surface can’t be expressed by stationary analytic formula, and generally it expressed by discrete list point. Free-form lens can distribute light intensity freely,and control light angle、optical path difference etc. Specific light spot is formed in illumination surface, meanwhile the light energy utilization ratio is improved greatly. There are two kinds of methods about Free-form fabrication, and the first kind of method is that free-form is grinded by a small grinding head ,which is controlled by computer; its disadvantage is low precision、high waster rate，especially for optical material; The second kind fabricating method is that multi-degree-of-freedom single-point diamond turning equipment; its disadvantage is that plenty of sub-micron crack formed when brittle material fabricated. In addition, micro-lens array element can’t be fabricated by the two kinds of methods. In allusion to the feature of free-form without stationary analytic formula ,which varying dose exposure lithography method for free-form micro-optical element is presented for free-form micro-lens and array. The method is from the theory that the relation between different exposure energy and different developing depth, adopting laser direct writing equipment free-form photoresist structure is formed in material surface, then the free-form photoresist structure is transfered on the substrate by ion etching method. Any surface figure can be fabricated by controlling every point laser energy for this method, and surface roughness can’t be effected because ion etching belongs to nanofabrication. In this paper, that low Distribution of light amplitude and relation of between exposure energy and exposure time was analysised on base of optical propagation theory and mathematical model of light distribution law was built and simulated by computer program.The results indicate that light energy distributes in accordance with specific law; the exposure depth increases with exposure time. The experiment of exposure and developing finished, used the BOL-500 laser direct writing system in Changchun University of Science and technology,american Futurrex62A photoresist, 412nn He-Ne laser device, 5‰NaOH developing solution. The experimental data coincide with simulation result via comparative analysis. Meanwhile，a set of free-form micro-lens array testing system was established and focal spot shape,energy distribution,focal distance,F parameter were tested about the micro-lens array.
Small Pitch Tool for Removing Middle Spatial Frequency Errors
Authors: Wang Gao Wen
Published: May 2013

More and more optical elements are needed in modern industry, which is reflected by both the bigger amount of requirement, and more complicated designed surface such as asphere and even free form surface. As a result, optical polishing using small tools on CNC machines is applied widely in the whole world, which has a lot of advantages such as fast speed, high accuracy, high flexibility and so on. But the small tool polishing can also cause in some problems. For example, the middle spatial frequency errors (MSFE) may be increased during the polishing. The reasons may consist of the following aspects: 1) the positional error of the workpiece; 2) the mistake of error data input; 3) the unexpected stop of the polishing process; 4) the stabilization of the slurry density during the process; 5) the temperature change of the contact area between the tool and the workpiece and so on. As is known, pitch is usually used in traditional optical manufacture, and it can reduce the middle and high spatial frequency errors in a large extent because of the different removal rate between the high points and low points on the optical surface. Therefore, the application of the combination of pitch and small tool is described in this paper in order to solve the MSFE problem, and we have got good polishing results of reducing the error from 2.155nm to 0.267nm by using the new pitch tool on the CNC machine after two runs.
Ion Beam Figuring Fabricate Effect with Different Removal Sizes
Authors: Gu Yong Qiang
Published: May 2013

Ion Beam Figure (IBF) is believed to be one of the most effective technics that can fabricate lens with nano or even sub-nano accuracy. For different sizes of IBF removal functions, the correct effects in different spatial frequency range are different. Power Spectral Density (PSD) curve can describe surface errors in full spatial frequency range, so it is a very convenient way to evaluate the quality of lens’ surface. In this paper, firstly, the principles of IBF and PSD are introduced briefly; Secondly, IBF removal functions with sizes from 2 mm to 15 mm are generated. A lens with surface error more than PV value 400nm is simulated with different sizes of IBF removal functions by Lucy-Richardson algorithm. Finally, experiments are done by IBF plant. A lens is fabricated by different sizes of removal functions and the fabricate results are tested by interferometer precisely and calculated to PSD curves. By the comparison of these curves, the IBF fabricate effects with different removal sizes are analyzed, which show that the smaller the removal size, the better the removal effect in higher spatial frequency range, but in the meantime, it will take a much longer time. Also the reasons of the difference between theory simulation and actual fabrication result are taken into account, and several influence factors are analyzed.
Study and Fabrication of Multi-Band Filter Film on ZnS Substrate
Authors: Zhang Jing , Sun De Gui , Fu Xiu Hua , Liu Dong Mei
Published: May 2013

In order to satisfy the special requirements of IR optical instrument, multi-band filter film on the substrate of ZnS is deposited by adopting electron beam vacuum depositing method with the ion assistant deposition technology. At incident angle of 0°～25°, 660nm high reflection and 1064nm and 3～5μm high transmission are realized. ZnS and YbF3 are selected as the high and low refractive index materials, and the film structure prepared easily is getting by optimizing the film system design curve ceaselessly. The precision of thickness control has been improved by adjusting film process parameters and improving film thickness control methods. The adhesion and firmness of film and substrate has been increased by pre-coating and mixed evaporation technology, and the laser induced damage threshold of film has been improved with vacuum annealing. The deposited film can endure the environmental tests such as rain pour, salt fog, and high and low temperature etc, and meet its practical requirement.
Research on Preparation Band-Pass Filter by Lon Beam Sputtering
Authors: Tang Hao Long , Fu Xiu Hua , Liu Guo Jun
Published: May 2013

According to the requirement of the filter for laser tracking system, we chose Ta as the target material of high refractive index and SiO2 as the target material of low refractive index, the film system was designed and optimized with the TFCalc software, adopted the double ion sputter coaters by VEECO company for plating system, using two sides of the substrate to broaden the long and short wavelength cut-off band respectively, we improved the peak transmittance and simplified the difficulty of experimental analysis, the filter to meet the demand has been deposited. The average transmittance of the filter at 532nm, 808nm, 1064nm and1550nm wavelength was less than 0.2% and the peak transmittance at 905nm wavelength was 96.3%. The filter can withstand the test of bad environment and satisfy the requirements of the laser tracking system.
Symmetric Distortion Correction in Asphere Manufacturing
Authors: Zhang Jian , Dai Lei
Published: May 2013

A method of symmetric distortion correction is described and successfully applied to correct the distortion mapping errors caused by CGH as well as internal imaging optics. The aspheric surface is 160 mm in diameter and has a maximum departure of 145 μm. According to the model established by the fiducial spots on the aspheric surface, we show experimental results after direct measurement and distortion-corrected error map respectively. The results show that the method of symmetric distortion correction is useful and effective.
Study of Optical and Electrical Properties of Ag/ITO Multi-Layer Transparent Electrodes
Authors: Wang Min Rui , Yu Bin , Wang Yu Xia
Published: May 2013

The samples of Ag/ITO multilayer films with different Ag insert layer thickness (0.5, 2, 4 nm) were prepared on sapphire and p-GaN substrates. The effects of the Ag layer thickness, annealing temperature and annealing time on the transmittance, sheet resistance and specific contact resistance of Ag/ITO films were investigated. The experiment results show that the transmittance is obviously affected by Ag insert layer thickness. The Current–voltage (I–V) measurements indicate that the sheet resistance and specific contact resistance of Ag/ITO film on p-GaN are lower than those of single ITO film. The samples with Ag(0.5nm)/ITO film on p-GaN produce the low specific contact resistance of ~1.386×10-4Ω•cm2 , low sheet resistance of ~11Ω/sq and high transmittance of ~ 90% at 455nm when the samples are annealed at 600°C for 10 minutes.
Reverse Design of the Roof Diamond Tool for Ruling Echelle Grating
Authors: Shi Guang Feng , Shi Guo Quan , Song Lin Sen
Published: May 2013

For precise geometrical design and wear-resisting design of the roof diamond tool for ruling echelle grating of large area, computer aided reverse design was used to solve the problems. Firstly, based on the mechanical parameters of grating， Al film got from the nanoindentation test and nanoindenting simulated analysis. The optimized geometrical parameters of the roof diamond tool are got with an orthogonal analysis in a dynamical finite element model of simulating mechanical ruling. Then an equivalent resistance design method is put forward to improve the wearable ability of the roof diamond cutter with wear simulated analysis. Finally, a roof diamond tool of trial-lapping is presented for grating ruling investigation to verify the design effect.
The Research on Preparation Process Optimization of Ion Barrier Film on the Input Side of MCP
Authors: Zhang Ni , Shi Feng , Zhu Yu Feng , Cheng Hong Chang , Nie Jing , Zhang Tai Min , Liu Xiao Jian , Yan Lei , Cheng Wei
Published: May 2013

Micro-channel Plate (MCP) with Ion Barrier Film(IBF) is one of the main technical indicators that restrict the performance of the third generations of Low Light Level Image Intensifier(LLLII). IBF with inferior quality can be a direct impact on the performance of the third generations of LLLII or even makes it not work, and it’s very unfavorable in the tube mass production and promotion. In response to this urgent requirement, in order to improve the quality and preparation of the finished product of the Al2O3 on the input side of MCP prepared by magnetron sputtering, the paper carries out the process optimization of magnetron sputtering used for image intensifier. By simulation of Ar ion bombarding Al2O3 target, while under the guidance of the working principles of the magnetron sputtering and thin film growth theory, we change the working pressure、 sputtering power、 argon flow and other process parameters by using magnetron sputtering machine developed in China, to change the coating deposition rate of Al2O3, and to increase the lateral migration of the film-forming process of Al2O3. Finally we prepare a uniform、 continuous and compact Al2O3 Ion Barrier Film. At last the optimal technique is obtained: Sputtering pressure is 2.6×10-1Pa, Ar2 flux is 90sccm, sputtering power is 170W, and the thickness of film is 80Å. We test the performance of MCP with optimized films by using the MCP performance testing devices, contrasting with pre-fabricated thin-film quality, and the results show that the average gain decline is dropped, the dead volt is lower, and the quality of the films prepared by this process is significantly better, yield and view pass rate is as high as 90%, meeting the dual demands of high electronic transmittance and high ion blocking rate of IBF.
Monte Carlo Simulation of Electron Scattering in Ion Barrier Film in Generation III Image Intensifier
Authors: Cheng Yao Jing , Yan Lei , Shi Feng , Liu Feng , Li Min , Shi Hong Li , Hou Zhi Peng
Published: May 2013

In Generation III image intensifier tubes, the input of the microchannel plate is typically coated with a thin Al2O3 film to prevent ions penetrating and damaging the delicate Cs-O activation layer of GaAs cathode. While the application of an ion barrier film to the MCP greatly improves the mean time to failure of the image intensifier tube, it unfortunately produces electron scattering to cause a significant degradation in the Modulation Transfer Function and resolution of the image tubes. To obtain an overview of the role of the ion barrier in Generation III image intensifiers, in this paper, we present the results of a Monte Carlo simulation on scattering electron transport through Al2O3 film with various photocathode voltage, density, thickness, and stoichiometry. Using Monte Carlo simulation on scattering electron ways, we get the MTF curve of film at the accelerating voltage of 400v, a thickness of 10nm, and a density of 0.3 g/cm3. The simulation results play an important role on optimizing the quality and facture technique of ion barrier film.
Characterization of Cutting-Induced Heat Generation in Ultra-Precision Milling of Aluminium Alloy 6061
Authors: Wang Su Juan , To Suet , Chen Xin Du
Published: May 2013

The technology of ultra-precision machining with single crystal diamond tool produces advanced components with higher dimensional accuracy and better surface quality. The cutting-induced heat results in high temperature and stress at the chip-tool and tool-workpiece interfaces therefore affects the materials and the cutting tool as well as the surface quality. In the ultra-precision machining of al6061, the cutting-induced heat generates precipitates on the machined surface and those precipitates induce imperfections on the machined surface. This paper uses the time-temperature-precipitation characteristics of aluminum alloy 6061 (al6061) to investigate the effect of feed rate on the cutting-induced heat generation in ultra-precision multi-axis milling process. The effect of feed rate and feed direction on the generation of precipitates and surface roughness in ultra-precision raster milling (UPRM) is studied. Experimental results show that heat generation in horizontal cutting is less than that in vertical cutting and a larger feed rate generates more heat on the machined workpiece. A smaller feed rate produces a better surface finish and under a larger feed rate, scratch marks are produced by the generated precipitates and increase surface roughness.
Maskless Lithography Based on DMD
Authors: Zhong Ke Jun , Gao Yi Qing , Li Feng
Published: May 2013

Largely owing to the high cost of masks for lithography, recently there is a strong interest in maskless lithography. Maskless lithography is a potential program to overcome the high cost caused by rising price of the masks. Because of the advantages of low cost, high flexibility and short production cycle, digital mirror device (DMD)-based maskless lithography has been brought storm attention by people. Both the theory and experiment of DMD-based maskless lithography achieved good results. Maskless lithography systems based on DMD are analyzed in this review. Principles of construction, examples of implication, as well as future development direction are discussed.
Infrared Telephoto Design Used in Joint Transform Correlator
Authors: Xu Chun Yun , Dong Jia Ning , Zhang Su , Wang Wen Sheng
Published: May 2013

In order to meet the requirement of tank sight and improve the ability of Joint Transform Correlator(JTC) in target detection and recognition, the infrared telephoto system with high image quality and high performance-price ratio is designed for wavelength 8μm～12μm. Initial structure is composed of four refractive lenses. The focal length is 200 mm, the relative aperture is 1:2.6 and image field of view is 1 inch (CCD). Considering the fabrication process, production cost and other factors, the system structure is further improved. First the telephoto which is composed of four lenses is designed with normal spherical surface. Then on the basis of the original spherical structure, an aspheric surface is introduced. The optical system can be reduced into three lenses. The image quality of the whole system becomes much better. The optical system image quality is evaluated with ZEMAX optical design software. The result shows that MTF of each field is close to the diffraction-limited curve at the cut-off frequency 17lp/mm. The spot diagram RMS radiuses are smaller than the radius of Airy disk 25.35μm. The wave front aberrations for all the fields are less than 0.25λ. The telephoto can meet the requirement of target detection. Combining JTC with this infrared telephoto lens, the infrared target at longer distance can be detected and recognized.
Modelling and Optimization of DLC Film Thickness Variation for PECVD Processes
Authors: Li Zhuo Lin , Fu Xiu Hua , Lu Jing , Yang Yong Liang , Sun De Gui
Published: May 2013

This paper describes a modeling method for film thickness variation within plasma enhanced chemical vapour deposition (PECVD) processes. The model enables the identification and optimization of deposition process sensitivities to electrode configuration, deposition system design and gas flow distribution. An comparison between theory and experiment is provided for PECVD of diamond-like-carbon (DLC) deposition onto flat and curved substrate geometries. This process utilizes butane reactive feedstock with an argon carrier gas. Radio-frequency plasma is used. The PECVD deposition system is based on co-planar 300mm diameter electrodes with separate RF power matching to each electrode. The system has capability to adjust the electrode separation as a parameter to optimize uniformity. Vacuum is achieved using dry pumps with real time control of butterfly valve position for active pressure control. Deposited film thickness sensitivities to electrode geometry, plasma power density, and pressure and gas flow distribution are demonstrated. In addition to film thickness uniformity, optical, durability and environmental performance of resulting DLC on germanium substrate materialreported.
Removal Method of Core Shaft of Primary Mirror
Authors: Xu Qi Rui , Wu Fan
Published: May 2013

The structure of core shaft combined with mercury belt is widely used as the primary mirror supporting structure of 1 meter class and 2 meter class large aperture telescope currently. In order to reduce the structure jitter of primary mirror, the fitting clearance between core shaft and shaft sleeve is very small, so clamping stagnation occurs during installation and disassembling process of core shaft. The removal method of clamping stagnation of core shaft is introduced. Mechanical analysis of core shaft and primary mirror is applied to make sure that the primary mirror is safe. Some tools are designed specially, and the process and the attention points to remove core shaft are introduced. In this way, the clamping stagnation of core shaft can be removed easily. The core shaft of 1 m class primary mirror was removed by the method and the primary mirror was excellent without damage.
Clitella Magnetorheological Finishing Method and Equipment
Authors: Yang Zhi Qiang , Guo Zhong Da , Liu Wei Guo
Published: May 2013

Clitella magnetorheological finishing is a processing ultra-smooth surface method, which has high processing efficiency and relatively low precision machine tool mechanical structure. This paper introduced processing methods that use a clitella magnetorheological finishing technology to achieve an arbitrary radius of curvature of the spherical optical parts. The paper design the device and use this device to process experiments. The experimental results have shown that this method can process optical parts.
Study on the Control System of Area-Contact Magnetorheological Finishing Machine
Authors: Chen Zhi Li , An Yong Gang , Zhang Zhao Shi
Published: May 2013

To achieve the goal of processing large diameter and ultra-smooth optical components, the control system of the area-contact magnetorheological finishing machine is introduced. The system includes motion control systems, structural adjustment systems, detection systems and alarm systems. PLC, the core of the system, is used to data collection, input and output control, process control and so on. The touch screen as the man-machine interface is simple and intuitive, easily to operate. This paper describes the algorithms of this control system and introduces the design of the hardware and software of the system. This control system have a stability performance, strong anti-interference ability. The result shows that the magnetorheological finishing machine could processφ300mm optical components the optical components, radius range of optical components is -∞≤R-30 or 30≤R≤∞, and the surface roughness less than 1nm.
Study of Polishing Technology for Aspheric Surface with High Efficiency
Authors: Li Yan Hong , Yang Li Bao , Cao Xiao Jun
Published: May 2013

In recent years, for the compact system structure of aspheric lens, it has improved the image quality and excellent performance. More and more applications, in a variety of precision instruments, require the aspheric surface machining precision, fast, batch production. In order to further seek the effective method of aspheric surface processing, the aspheric NC machining technology is put forward. Therefore, this paper studies the aspheric surface in NC machining process of milling molding, polishing and polishing equipment related process parameters. Focusing on the milling process of various parameter settings, the resilient mold and small grinding head fixed combination method of polishing is introduced into the milling feedback compensation, solution of the elastic die polishing on the profile accuracy of destruction and processing to meet the requirements of the drawings of components: the contour measurement method on the profile accuracy of testing and surface shape accuracy of 0.5924um.
Design of Long-Wave Infrared Scan System with Rotating Dual-Wedge Prism
Authors: Fan Zhe Yuan , Gao Li Min , Yang Hong Tao , Chen Wei Ning , Cao Jian Zhong , Zhang Jian , Zhang Zhi
Published: May 2013

Due to the possession of advantages of passivity working mode, good disguise, and easy observation, infrared systems are used in a wide variety of applications. This paper using 640×480 uncooled detector designed a long-wave scan optical system with large field and large aperture working at 8.0μm～12μm, the Pixel Dimensions of the detector is 30μm. The F number of this system is 1.4 and focal length is 17mm, FOV is 63.6°, which extended to 143° by adopting dual-wedge prism rotating, the paper also given the extended field theory by the dual-wedge prism. Because there are a limited number of lens materials used in LWIR spectral bands, Germanium material and three aspheric surfaces were adopted to balance sphere aberrations and chromatic aberration. All above mentioned are intending to ensure the system has good imaging quality. The results show that the optical performance approximates to the diffraction limit and the design has better achromatic performance. The modulation transfer function (MTF) is above 0.5 at spatial frequency of 20lp/mm, energy concentration ratio is greater than 70% within the sensing element of the detector and Root Mean Square (RMS) value of spot diameter is smaller than the Pixel Dimensions. The system has advantages of simple structure, large aperture, high image quality etc.
Analyses the Character of GaAs Photocathode by Diffraction Curve from Spectrophotometer
Authors: Cheng Wei , Hu Cang Lu , Jiao Gang Cheng , Miao Zhuang , Zhang Ni
Published: May 2013

Transmissivity and reflectivity of GaAs photocathode get from spectrophotometer are measured and analyzed according to various wave bands, so that the corresponding optics parameter is obtained. The typical optics parameter of various GaAs photocathode has been summarized. For blue-light extension photocathode, the diffraction peak will be close to ultraviolet wave band from the reflection curve. The thickness of Active layer film and optimal Si3N4 film on the GaAlAs layer have been acquired. The experimental and analyzed results have shown that the Si3N4 film on the GaAlAs layer should be about 1000A when the the GaAs photocathode got the optimum performance.The thickness of Active layer film should not be too thick to escape of electron and too thin to transfer of photon-electron. The experiment shows that the spectrophotometer can analyze epitaxial material and assist the manufacture of GaAs photocathode.
High Precision Machine Vision System for Outer Diameter Inspection Bearing
Authors: Gao Yuan , Zhang Guo Yu
Published: May 2013

A machine vision system for bearing outer diameter inspection has been developed in this paper. The infinite objective of optical system is applied to diameter measurement system. The paper provides a method for measuring the size of objects based on polynomial interpolation. The technology of CCD image stagger is applied in the paper. The method can avoid space between pixels astriction theoretically, so higher measurement accuracy is gained. The experiment results show that the system has many advantages such as non- touch , high speed and higher precision.
Error Analysis of Optical Alignment Based on Multi-Beam Splitting
Authors: Zhang Lei , Li Zhuo Lin , Liu Zhi Ying
Published: May 2013

Beam splitter is widely applied in many optical systems. The beam splitter is generally composed of many reflective mirrors and beam splitting prisms. The optical components can not reach the theoretical design state during assemble process. It must be solved through optical alignment. The mathematics model of alignment and error analysis for beam splitter are built in this paper. The effect of optical alignment error of beam splitter on optical system could be analyzed with this mathematical model. At the mean time, the mechanical alignment of beam splitter is directed to fast alignment in practical process. One kind of optical communication system is shown as example. The optical transmitting exit is commonly used. The requirement of axis parallelism of sub-systems is very strict. The axis parallelism between sub-systems reaches 5’’ in experiment with this model application.
Design of a Refractive/Diffractive Hybrid Middle Infrared Continuous Zoom Optical System
Authors: Hu Dan Dan , Zhao Jian Ke , Xue Xun , Liu Feng , Zhang Jie , Xu Liang
Published: May 2013

The application of diffractive surface in the continuous zoom system is investigated by taking advantage of the negative dispersion characteristics of binary elements. A sample design is presented in this paper using cool 320×240 detector with staring focal plane array and secondary imaging, and a mid-wave optical system using mechanical-compensated with refractive/diffractive hybrid technique is designed. The Pixel Dimensions of the detector is 30μm, and the wavelength between 3.7μm ~4.8μm.The system adopts negative group variable times and positive group of compensation which can realize 18mm～180mm continuous zoom and FOV =36.8°~3.8° , F-number is 2, it consists of 7 lenses including 2 aspheric surface and 1 diffractive surface. The length of this system is 230mm with the reflection mirror to shorten optical path. The results show that the modulation transfer function(MTF) is above 0.6 within the whole focal range at spatial frequency of 17 lp/mm, and Root Mean Square (RMS) value of spot diameter were smaller than the Pixel Dimensions. After the image quality being optimized, the monotonic and smooth cam curve is given and 100% cold shield efficiency is obtained. The curve shows that the imaging plane is stable and the cam is easy to process. The system has advantages of simple structure, high image quality and short zoom path etc.
Analysis of Influence of Beam Expender Parameters on Coupling Efficiency of Single Mode Fiber Used in Lidar
Authors: Sheng Hong Jiang , Mao Jian Dong , Li Xue Sheng
Published: May 2013

Based on theoretical analysis, the beam expender used in all fiber lidar with a coupling efficiency of single mode fiber (SMF) is investigated. Some numerical computations are carried out and following results are obtained. For all fiber lidar in order to get the maximum coupling efficiency on SMF, the relationship between the distance d, ranged from the secondary to primary lens of the beam expender, and the laser waist spot location l, which is at a distance from the secondary lens of beam expender are obtained. And also the relationship between l and the measurable bandwidth is analyzed. Under the condition that if the laser location is certain and the imagine spot location is infinite, with adjusting the distance d which can make the image spot size obtain its minimum, the maximum coupling efficiency about 70.6% is got and the adjusting range of d has only 0.2~0.9mm. Assuming that the image spot distance is infinite, and the minimum of spot radius is got after the laser waist spot goes through the beam expender, the function between d and l is retrieved by use of laser propagation theory. By comparing the theoretical curve with the computing one, the theoretical function agrees with the numerical computing curve approximately. These conclusions have the important directive significance for design of all fiber Lidar.
Parameters Determination and Theoretical Modeling of Tm-Doped Fiber Lasers
Authors: Tao Meng Meng , Yang Peng Ling , Huang Qi Jie , Yu Ting , Ye Xi Sheng
Published: May 2013

Determination of parameters is presented in the modeling of Tm-doped fiber lasers. The thesis chooses parameters, numerical simulation to examine the performance of the laser system for different pump schemes and cavity parameters. Their impacts on the laser performance are discussed.
Influence of Laser Scribing System in the Electrical Properties for a-Si Thin Film Solar Cell Preparation
Authors: Chen Xue Song , Chen Xin , Chen Xin Du , Yang Ming Sheng
Published: May 2013

Laser scribing of hydrogenated amorphous silicon (a-Si) is a crucial step in the fabrication of thin film photovoltaic modules. The required line width of the laser scribing process for a-Si thin film solar cell preparation is 30 m~50 m, the dead zone is less than 300 m in size, and the line depth should be compliant with the process requirements. Thus, the high imaging quality and focal depth of the optical system is required in the laser scribing system. Three crucial laser patterning steps (known as P1, P2 and P3 in the photovoltaic literature) are integrated in the thin film silicon module manufacturing sequence. Therefore, efforts to optimize these laser processes are demanded by the photovoltaic industry. In particular, the state of the remaining material after laser treatment is known to have a critical influence on the electrical properties of the final devices. This paper focuses on the P3 laser scribing process with the peculiarity that it has been done in single solar cells. By evaluating it in single solar cells rather than in finished module, it is possible to isolate its effect on the device characteristics since the P1 and P2 scribings are omitted. To study the effect of the P3 scribing length, several scribings can be done in the same cell. As it will be shown, the high speed motion systems needed for precision laser scribing plays an important role in this experiment. They can be responsible for the electrical losses after the scribing of the solar cells. If this is dealt with properly, it can be seen that the P3 scribings have very little effect on the electrical characteristics of the processed solar cells.
Dual-Wavelength Single-Mode Optical Fiber Raman Laser
Authors: Huang Qiu Shi , Cai Hong Xing , Zhang Xi He , Qu Yan Ji , Wei Zhi , Peng Bo , Tan Yong
Published: May 2013

In order to realize the dual-wave length lasing based on stimulated Raman scattering principle, the dual-wavelength single-mode optical fiber Raman laser is established. Firstly, 80m long G652b single-model quartz fiber is pumped by Nd3+:YAG solid pulse laser, and its output spectra when without grating which are measured and studied. Then, a linear external-cavity fiber laser is designed with fiber Bragg grating as mirrors to gain 1062nm and 1066.5nm laser output. To change pump energy (65.2uJ~100.4uJ), the mean-variances of energy percentages are all about 7.58%,and dual-wavelength energy ratio is close to 1:1. Pump pulse widths are close to 32.14ns. Finally, the main parameters of laser are analyzed too. The dual-wavelength single-mode optical fiber Raman laser can be applied to Raman amplifier filed.
Structural Improvement of 920 nm Optically Pumped Semiconductor Vertical External-Cavity Surface Emitting Laser (OPS-VECSEL)
Authors: Liang Xue Mei , Qin Li , Ning Yong Qiang , Liu Yun , Wang Li Jun
Published: May 2013

920 nm OPS-VECSEL has an important application in laser display. We constructed and optimized a 920 nm optically pumped semiconductor vertical external-cavity surface emitting laser (OPS-VECSEL) with active region of In0.09Ga0.91As quantum well (QW) system pumped by 808 nm laser diode module. By the finite element method, self-consistent solutions of the semiconductor electronic and optical equations are realized to calculate the characteristics parameters of OPS-VECSEL. The performances of device, especially the mode, the threshold and the optical-optical translation efficiency, were analyzed by dealing with different numbers of QWs (1, 2 and 3) in one period, QW depth, barrier width, the component and dimension of the non-absorption layer. We chose the best structure of them. On this basis, we optimized the external cavity mirrors reflectivity and the simulation showed that the performances would be significantly increased.
Stochastic Resonance in a Single-Mode Laser System with an Input Pulse Signal
Authors: Zhang Li , Yuan Xiu Hua
Published: May 2013

In this paper, we investigated the stochastic resonance (SR) phenomenon in a laser system with correlated pump noise and quantum noise. The signal-to-noise ratio (SNR) is calculated when a square sine pulse signal is added to the system. The effects of the duty cycle of pulse signal and the correlation strength of noises on the SNR are discussed. Some valuable phenomena are investigated to improve the output SNR of laser.
Athermalization of Long Focal Length IR Optical Systems by Hydraulics
Authors: Zhao Jun Yan , Du Guang Hu , Qin Zhi Peng
Published: May 2013

The effects of temperature changes on the focus of IR optical system are described in this paper, and the general methods used for compensation of thermal effects are analyzed. On this basis, the feasibility of athermalization of long focal length IR optical systems by using of hydraulics is studied, and an athermalization design of an uncooled IR optical system with focal length 200mm and F-number 1 is presented. The result shows that within the temperature range from -30 to 50 °C, the defocus of this system is less than the depth of focus.
Testing System for Low Power Laser Beam Divergence Angle of Visible - Near Infrared Optoelectronic Sights Based on Virtual Instrument
Authors: Zhang Lei , Zhu Da Zhao , An Zhi Yong
Published: May 2013

According to current situation of testing beam divergence angle of low power laser indicator, this paper is designed to develop a testing system for beam divergence angle of low power laser indicator based on virtual instrument. A sport utility is used in this system - data acquisition card for the displacement data acquisition and motion control and a video card for images acquisition. The use of labview graphical programming language to develop host computer program including Man-machine Interface and functional code, realizes Data acquisition, process, display, storage and motion control; ensures the system accurate and efficient.
MBE Growth of 2.3μm InGaAsSb/AlGaAsSb Strained Multiple Quantum Well Diode Lasers
Authors: Zhang Tian Cheng , Ni Qin Fei , Liu Xue Zhen , Yu Bin , Wang Yu Xia , Zhang Yu , Ma Xun Peng , Wang Yong Bin , Xu Yun
Published: May 2013

2.3 μm InGaAsSb/AlGaAsSb lasers with multiple quantum wells(MQWs) have been demonstrated.The growth temperature of quantum wells is 440°C,and the growth quality of InGaAsSb/AlGaAsSb MQWs is examined by X-ray diffraction and Photoluminescence(PL) at room temperature.The energy band structure of MQWs was calculated by one-dimensional finite-difference method(1D-FDM)
Spatial Resolution Improvement of Distributed Optical Fiber Raman Temperature Sensor System by Using Amplitude Modification Algorithm
Authors: Jin Zhong Xie , Zhu Hai Peng
Published: May 2013

Spatial resolution is an important parameter in distributed optical fiber Raman temperature sensor system (DOFRTS). In this paper, a 10 kilometers long DOFRTS with spatial resolution of about 6 meters is constructed. The spatial resolution is limited by electrical bandwidth of the photodetector circuit and the data acquisition part. The abrupt temperature changes along the fiber axis are treated as temporal pulse signals, and a linear amplitude coefficient modification algorithm is used to improve the spatial resolution. The experimental results show that the temperature amplitudes from 3 meters region to 6 meters can be modified accurately. Therefore, a DOFRTS of high spatial resolution but low system cost could be successfully constructed.
The Research of Controlling Constant Temperature for Semiconductor Laser Diodes
Authors: Bai Duan Yuan , Gao Xin , Bo Bao Xue
Published: May 2013

This paper introduces two types of precise temperature controllers for high power semiconductor laser diodes. We apply a category of self-tuning parameter fuzzy-PID controller，and a kind of neuronal network optimized rules fuzzy-PID controller to realize stable temperature controlling. we simulate these two methods by Matlab. The result proves that the new method has more superiority than traditional means, such as PID controlling, etc. And further improvement on constant temperature control will inevitably promote the reliability of LD.
Modeling and Optimal Design of Membrane Based Fast-Tool-Servo for Freeform Manufacturing of Micro Optical Lens Array
Authors: Yang Zhi Jun , Zhou Wei Bo , Chen Xin , Chen Xin Du , Li Ke Tian
Published: May 2013

The Fast-Tool-Servo (FTS) is widely used for micro-structure manufacturing especially for micro optical lens. The working principle of FTS presented by Qiang Liu et.al is that, a voice coil motor and a piezoelectric（PZT） actuator are used as the driving elements, and two flexure hinges are developed as the guide mechanisms. However, vertical displacement jump happens when the flexure hinges are driven by a voice coil motor or a piezoelectric actuator. In this paper, a new amplified structure is presented, allowing the horizontal motion while reducing the vertical displacement jump. The working principle is that, the piezoelectric actuator is applied to a beam which has two flexure hinges, one is linked to the frame, and the other is linked to a tool holder which is situated through two parallel membranes. When the piezoelectric actuator deforms, the beam will rotate around the frame, while the displacement is amplified at the other end, causing the tool holder’s motion and the membranes are forced to bend, while the vertical motion is restrained by the membranes. As a result, the presented membrane based flexure structure is able to amplify the motion of the piezoelectric actuator. In addition, the vibration frequency of the membrane is easy to be adjusted by the preloaded force. It is important to know when the FTS is working at different frequency. The performance of the presented structure is analyzed by structural dynamics coupled with piezoelectric, and the parameters of the structure are optimized to remain linear relation between the tool holder and the piezoelectric actuator, while the vertical displacement jump is much smaller than the structure presented in reference.
Study on Radius of Curvature Measurement System by Interferometry
Authors: Dai Lei , Wang Gao Wen , Sui Yong Xin
Published: May 2013

This paper deigns a new ROC measurement system for radius of curvature of spherical surface measurement base on interferometry. The ROC measurement system is designed compactly and continently to use. The ROC measurement range is up to 2000mm, and DIA of the spherical surface is range from 100mm to 300mm. We analyze the uncertainty sources of the ROC measurement system results and calculate combined standard uncertainty. Giving out the experiment results, the relative uncertainty is less than 6.9ppm (ROC~1500mm). By discussing the method, we can improve and reduce the uncertainty of results of ROC measurement system.
Research on the Online Test Principle and Error Analysis of Aspherical Optical Surfaces
Authors: Mu Da , Li Quan Yong , Wu Bo Qi , Du Yu Nan
Published: May 2013

For tFor t For tFor the imaging advantages of aspheric optical component, it has been widely used in the aviation, aerospace, defense and civilian high-technology. Aspherical surface shape test is a key factor restricted aspheric processing and a complex sophisticated testing techniques. The well known measurement methods are faulty. Each method has advantages and disadvantages; many methods cannot be used for online testing. In this paper，the geometric principle of a swing-arm profilometer as a novel method to measure aspherics is introduced．The deviation between the actual and the ideal of aspherical surface shape is confirmed by the high-precision measurement for the vertical height with a specific path on the aspherical optical surfaces. By adjusting the location of measuring devices to maintain the distance of rotation center to the center of workpiece equal to the length of swing-arm,we can achieve the measurement for the workpiece of different machining tool. The measurement system mainly consists of the lifting and landing system of the high-precision axis,the high-precision level turntable rotary table, the high rigidity measuring arm and the high precision measurement sensors. And the follow-up data processing puts forward a number of error correction models at the same time. The advantages of the measurement method are that the measurement sports is only a simple turning motion .It will be helpful to reduce measurement errors and improve the efficiency of measurement.
Target Optimization Design of Cam Curve in Zoom System
Authors: Ning Chen Wei , Zhong Cao Jian , Tao Yang Hong , Jian Zhang , Yuan Fan Zhe , Li Wu , Hui Zhang , Jie Lei Yang
Published: May 2013

Zoom lens has been widely applied in all kinds of fields, and its cam optimization is the key to actualizing the performance of its optical design and the zooming process, while the smoothness and speediness of zooming movement must be considered for military and civilian use. With the incremental use of environmental requirements, it puts forward higher requests to the cam performance of lens. In order to guarantee that the cam has good stiffness in the case of vibration and shock environment, in the process of cam design, it not only requires curve optimal, but also needs to consider influence on the performance which is caused by reduced cam stiffness of the zoom system. A fine curve can ensure that the cam pressure angle α is smaller, and to ensure the cam follower maintains the uniform velocity and smaller acceleration in zooming process, and make the zoom system produce little impact, and whole zooming process smooth and fluent, it can reduce the zoom systems driving moment M, and can ensure the stability imaging of the zoom system. Good cam stiffness K can make the zoom lens have good stability in vibration environment, and make sure that the image quality. M and K respectively up to the pressure angle α of zoom curve and the rotation angle θ of zoom curve in cam. In the new cam design process, considering the whole influence on the performance that is caused by K and M to cam, we construct the function expressions K = f (α, θ) and M = f (α, θ), and then, build target optimization function with K and M, optimize the relationship between pressure angle α of zoom curve and rotation angle θ, looking for the optimal value for the stiffness K and the cam system driving moment M , and improve overall performance of the zoom cam .
PID Algorithm Applied in the Refrigeration of EMBCCD
Authors: Zhao Lian , Liu Guang Rong , Liu Pan
Published: May 2013

For EMBCCD (Electron Multiplying Back Illuminated CCD) which is low light level imaging device, temperature has an important effect on the imaging performance. When EMBCCD enhances signal, it also amplifies the noise of the dark current. The most effective means of cooling chip is to reduce the noise of the dark current. When the EMBCCD is in the stable environment in low temperature, the signal to noise ratio can be improved. For this problem, the article describes the PID (Proportion Integration Differentiation) control algorithm. The unit step response curve for the controlled object is obtained by absolute refrigeration. As the system unit step response curve meets the requirements of the S-shaped curve, the Ziegler-Nichols method is used and the parameter is obtained from the S-shaped curve. The deviation between the actual temperature and set temperature values according to the proportional, integral and differential linear combination to form the control volume, incremental PID control algorithm. Put the parameters into the algorithm to control the refrigeration temperature. After that, the initial control curve is gotten. By repeated testing, we can get more appropriate parameters, and the temperature can be controlled at the target temperature. And the temperature curve is in the flat, almost with no fluctuation. The corresponding PID parameters and processing strategies are gotten from the debugging process. At last, calculate PID parameters and processing strategies, and implement the PID algorithm, as well as the numerical quantification of the specific applications the basic method are obtained. The experimental results show that the algorithm can make the temperature at 10.5°Cwith error0.5°C.
A New Method for Detecting Jet Impact Force of Laser Cavity
Authors: Li Ming , Xu Rong Qing
Published: May 2013

Based on the deflection effect resulted from deformation, a new experiment device for measuring the jet impact force of laser cavity is developed. The device has been used in experiment and the typical signal of jet impact force was obtained. The variational characteristic of the force with time was given. The result shows that during the experiment the target material sustains three forces. In order of time, the first force is the laser ablation force, and the other two forces are jet impact forces. The first jet impact force is greater than the ablation force and the second jet impact force is smaller than the first jet impact force.
Research on Simulator System of Multiple Interferences
Authors: Yu Jing Jiang , Li Ying , Fu Yue Gang , Xu Zheng Ping , Zhou Xun
Published: May 2013

The simulator provides a virtual emulational condition. It can test the functions of infrared missile by simulating the movement of the target and the interferes. A target simulator with multiple interferences is provided in this paper. The blackbody is used as radiating source. The simulator’s construction, principle and the realization of motion track are mentioned. It has been proved that the simulator can meet the demands of development of missile. And the simulator is universal because the interference source has three bands.