多用户自由立体显示技术

介绍了一种新型的多用户自由立体显示器的结构原理和背光实现方案.采用液晶显示屏,利用菲涅尔透镜的光学成像原理形成可视区域,背光板采用LED阵列分立控制,每一列都可以单独点亮,通过与人眼跟踪程序相互配合,对处在不同区域的观察者分别提供光源,使观察者在屏幕前的任何区域都可以观察到立体效果.实验采用930 mm焦距的菲涅尔透镜,光源距离屏幕839 mm,可以在显示屏前490～550 mm的位置处得到±30°的可以自由移动的立体视域,利用单片机控制系统,反应时间小于30 ms.     

基于空间调制器的透镜设计与成像研究

为了研究利用空间光调制器制作的菲涅尔透镜的特性,基于标量衍射理论推导了透镜的相位分布函数,建立了菲涅尔透镜的模型;并通过实验测量了空间光调制器的相位—灰度特性曲线,得到了相位与灰度的函数关系.制作了焦距为100 mm和150 mm的菲涅尔透镜相位灰度图.通过实验研究了该菲涅尔透镜成放大实像和缩小实像的成像规律;结果表明...     

自由立体显示中的背光系统设计

为实现自由立体显示,本文提出了一种新型指向性背光结构,配合人眼跟踪系统,分时显示具有视差的立体图像对,基于视差原理实现了高清分辨率的多用户自由立体显示。着重阐述了多光程结构、菲涅尔透镜以及掠入射的光路系统,以及从这三方面产生的效果。实验表明,三者的结合能产生良好的背光效果,最终实现了具有较强立体感的无分辨率损失的自由立体显示。     

基于人眼视觉特性的三维显示技术

人眼是三维显示的第一接受器官,在深度视觉、空间/时间分辨、颜色/亮度响应等过程有其独特作用。针对三维显示中的立体图像质量、观看舒适度和临场感特性,对自由立体显示器中立体视疲劳、表面形变、大视场角显示质量和色带效应进行研究,从柱透镜的脉冲响应函数出发进行分析,并提出解决方法,在此基础上将多视点自由立体显示用于澄江古生物群科普宣传。同时讨论了集成成像中单元图像处理、立体深度和显示分辨率的问题,以及全息显示技术中的人眼视觉特性。     

用于LED均匀照明的自由曲面菲涅耳TIR透镜光学设计

为了提高透镜的散热能力,设计了一种新型全内反射（TIR）透镜,该透镜的出射面中央为自由曲面菲涅耳面。采用斯涅尔定律和全反射定律分别求解TIR透镜折射部分和反射部分自由曲面的面形。同时,采用一种菲涅耳透镜的普适设计方法将折射部分自由曲面转变成菲涅耳面。通过蒙特卡洛光线追迹模拟自由曲面菲涅耳TIR透镜的照明效果,结果显示:当光源尺寸为2 mm×2 mm时,其远场照度均匀性为82%,光效为96.6%,透镜质量为21.94 g。与未加菲涅耳面的TIR透镜相比,带自由曲面菲涅耳面的TIR透镜在光效仅下降2%,在照度均匀性未变的情况下,透镜质量减少了约20%。这说明对TIR透镜的自由曲面出射面进行菲涅耳化可明显地缩小透镜的体积和质量,缩短光线在透镜内部的光程,因此可有效提高透镜的散热效率和使用寿命,同时保持良好的照明效果。     

高高宽比硬X射线聚焦波带片的制作

相对于软X射线显微成像,硬X射线显微成像对菲涅尔波带片的吸收体厚度提出了更高的要求.采用电子束光刻和X射线光刻复制的方法,在聚酰亚胺薄膜上成功制作了高高宽比的菲涅尔波带片.首先利用电子束光刻和微电镀技术制作了X射线光刻的掩模,然后利用X射线光刻和微电镀制作了高高宽比、线条侧壁陡直的菲涅尔波带片.复制后的波带片最外环宽度500 nm,直径1 mm,吸收体金厚度为3.6μm,高宽比达到7.2,可用于10 keV～25 keV的硬X射线成像.     

LED交通信号灯光学设计

设计了一款在规定角度范围内光强均匀分布且直观无明显的颗粒感的LED 交通信号灯。将高亮度LED 的出射光用菲涅耳透镜进行准直,利用斯涅尔定律,设计了枕型透镜来实现指定方向上的照明,并将之排成阵列,以获得一定角度范围内的光强均匀分布。利用ZEMAX 光学设计软件对设计方案进行了模拟,分别给出了水平和竖直两个方向上角度光强均匀分布的结果。通过仿真人眼对信号灯的成像,呈现人眼的观察效果,结果表明该设计满足设计要求。     

液晶菲涅尔波带透镜的电光特性研究

液晶菲涅尔波带透镜是基于液晶的电光效应来改变其折射率分布的新型透镜。在频率为100 Hz的交流电压驱动下,用UV-Vis 8500型紫外/可见分光光度计测量了液晶菲涅尔波带透镜三基色R(700.0 nm)、G(546.1 nm)、B(435.8 nm)的电光特性,得到三基色的T-V曲线。分别在0 V、1.0 V、3.0 V下,测量He-Ne激光通过液晶菲涅尔波带透镜后的光强,得到光强分布。结果表明,液晶菲涅尔波带透镜的阈值电压为1.0 V,且随着电压的改变,三基色透过率的变化趋势是一致的。同一波长的入射光在不同电压下通过透镜后,透镜的焦距不同。     

大口径线视场菲涅尔准直透镜设计

针对某一特殊应用设计了一款菲涅尔准直透镜,利用菲涅尔透镜的基面弯曲和单向点列半径的像差控制,实现了一维方向的高精度准直.分析比较了平面菲涅尔透镜与球基面菲涅尔透镜的像差状况,得出了两种结构透镜在本项目应用中校正像差的差异,提出了在类似菲涅尔透镜的应用中像差校正的方案及面型选择的思路.     

单透镜菲涅尔计算全息显示系统中多级像和零级光的去除

为了消除多级像和零级光的干扰,提出了一种单透镜结构的系统,获得了单一无扰的再现像.使用Gerchberg-Saxton(GS)算法获得菲涅尔全息图,预先叠加倾斜平面波相位至菲涅尔全息图上,使再现像移至中央位置.用成像透镜将空间光调制器(SLM)后方的虚像成像至前方,同时在成像透镜后方放置空间滤波器,滤去多级像和零级光.调整透镜与SLM的位置可方便调整再现像的大小和位置,缩短了光学系统的长度.利用虚像的方法为基于液晶SLM的计算全息显示提供了新的思路.     

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.     

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.     

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.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.