提高引伸计测量精度的小波去噪方法研究

介绍了利用线阵CCD引伸计测量形变量的原理和系统结构。利用小波变换对CCD输出信号进行处理,实现了滤除高频噪声、平滑输出曲线的效果。采用最小二乘法做曲线拟合,突破CCD光敏元尺寸限制,使位移精度达到CCD光敏尺寸的1／10。实验测量表明,材料形变测量精度达到1μm。     

基于Ethernet的线阵CCD数据采集系统

设计了一种基于Ethernet的线阵CCD数据采集系统,通过FPGA对线阵CCD输出的数据进行采集,并通过在FPGA生成的nios2软核中移植μClinux构建具有网络功能的嵌入式系统,然后通过Ethernet将线阵CCD数据传输到上位机.详细介绍了整个数据采集系统的硬件系统和软件,系统的设计和上位机接收软件的设计.实现了基于Ethernet线阵CCD图像采集,传输以及图像的接收.     

基于DSP和线阵CCD外螺纹几何参数非接触测量方法研究

为了提高外螺纹尺寸检测的精度并实现自动化测量,文章提出了基于线阵CCD的非接触测量方法,建立了包括图像数据自动采集和尺寸计算的测量系统,该系统通过控制高精度的线阵CCD扫描外螺纹在平行光场中的投影并结合光电编码器来获取螺纹图像。文章详细介绍了线阵CCD驱动电路的实现,以TMS320F2812为信号处理器的线阵CCD在线测量系统的硬件结构与软件设计。     

针孔法MTF测试系统测量精度分析

为确保光学调制传递函数(MTF)测试系统的精度,从针孔法MTF测试原理出发,对系统中各组件的固有误差、光电系统离焦、噪声等因素对调制传递函数测量精度的影响大小进行了计算及比较。结果表明光源的波长、显微物镜的放大倍数误差、光电系统离焦和噪声对系统的MTF测量精度都存在较大影响,需要严格加以控制。针孔尺寸和平行光管的焦距误差对测量结果的影响随针孔像尺寸变大迅速增大,应保证针孔像尺寸小于5μm。而CCD的像元尺寸误差在其换算到被测镜头像平面处的尺寸小于2μm时对测量精度几乎没有影响。     

线阵CCD测量系统的镜头畸变校正新方法

提出了一种线阵CCD测量系统镜头畸变校正的新方法.用线阵CCD相机及经纬仪组合体,对空间周期黑白条纹图像照相,通过图像处理和matlab曲线拟合建立图像像素坐标与无镜头畸变的理想像素坐标的关系式,即畸变校正函数.利用畸变校正函数可校正线阵CCD镜头畸变.将该方法应用于线阵CCD散布正交交汇测量系统后(两相机间距为1 561 mm),测量误差由畸变校正前5 mm提高到畸变校正后的0.9 mm.实验结果表明,用该方法进行镜头畸变校正后,线阵CCD散布测量系统的精度得到了显著的提高.     

基于线阵CCD的二维轮廓扫描系统

吊装过程中为获取吊物具体位置信息,设计了一种基于线阵CCD的二维轮廓扫描系统。利用激光照射直线与线阵CCD投影直线相交的原理求取激光照射点二维坐标;提出了一种基于硬件的线阵CCD脉冲中心位置测量方法;采用双直线法对线阵CCD进行标定,得到其输出像素坐标与投影直线的映射关系;研究提出了一种升降速控制策略,能平稳高效地控制步进电机。用已知尺寸的圆柱形PVC管作为实验对象,系统测得其二维轮廓若干离散点坐标,通过圆周拟合的方式得到圆柱半径,平均误差为0.928 mm,系统一次扫描耗时约0.45 s;实验结果表明,系统测量精度较高,扫描速度较快,可广泛应用于物体的二维轮廓扫描。     

线激光辅助面阵CCD光学成像弹丸位置解算模型北大核心CSCD

针对典型光电测试系统光幕结构复杂、测量精度低的问题,本文提出一种线激光辅助面阵CCD光学成像方法测量弹丸的位置信息;通过分析弹丸穿过激光光幕在面阵CCD上的成像原理,给出弹丸成像所占面阵CCD像元位置信息与弹丸空间位置的关联函数,结合线阵列光电探测器接收弹丸过幕信号的编码点位置,构建弹丸空间位置解算模型;根据仿真分析,在1 m×1 m探测区域内x,y坐标最大误差均小于3.5 mm;通过与木板靶测试进行对比实验,验证了激光辅助面阵CCD光学成像测量弹丸位置信息的科学性和正确性。     

基于多FPGA的高速尺寸测量系统设计

针对传统尺寸测量系统处理速度慢、测量精度低等问题,设计了一种基于多FPGA技术和高灵敏度线阵CCD图像采集单元的高速尺寸测量系统。该系统采用延迟锁相环技术实现时钟同步,调用FPGA内部存储器IP核,并引入乒乓操作的异步FIFO设计对数据进行缓存,再由接口电路传输至上位机,实现对多参数物体测量。各子模块功能均在Xilinx FPGA的编译环境ISE中进行综合,使用MODELSIM工具进行时序仿真。实验结果表明,该系统可以满足高精度、高速实时测量的要求。     

彩色线阵CCD用于物体尺寸精密测量的研究

现有精密尺寸测量系统采用单阵列的线阵CCD作为光电传感器,不能检测像元的排列方向与物体尺寸方向的夹角γ,而当夹角γ在测量中发生变化时将引起测量误差,本文采用彩色线阵CCD（TCD2901D）作为光电传感器进行精密尺寸测量,检测出夹角变化带来的尺寸测量误差,得到了误差的修正方法。     

基于双单片机的线阵CCD驱动及信号处理系统

针对线阵CCD器件的驱动和信号处理,使用了2片STC11F02单片机,一片产生CCD驱动时序信号,另一片负责测量控制及与上位机进行通信。采用硬件的方法对CCD输出信号进行处理,直接得到光斑中心位置,不需要进行A/D转换。试验结果说明测量精度可达0.007 mm。该电路成本低,体积小,速度快,可广泛应用于基于线阵CCD的非接触式几何量测量。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.