傅里叶分析法求Stokes矢量测量扭曲向列相液晶盒盒厚和扭曲角

本文提出了一种测量扭曲向列相液晶盒盒厚与扭曲角的新方法,在液晶盒和检偏器之间放置四分之一波片,通过旋转此四分之一波片,测量各个调制点的光强,用傅里叶分析法计算线偏振光穿过液晶盒后的 stokes 矢量,从而求出液晶盒盒厚以及扭曲角.实验证明,用此方法测量盒厚比较小的液晶盒厚有较高测量精度.另外,此方法也可以应用到单偏振片反射式液晶盒盒厚和扭曲角的测量.     

偏光干涉法测量液晶的双折射率

为了测量液晶双折射率,从偏光干涉的理论公式入手,通过一定的近似,采用偏光干涉法测量液晶双折射率,进行了理论分析和实验验证,获得了较为理想的数据。结果表明,在采用偏光干涉法测量液晶材料的双折射率时,避免了对透射光谱的绝对光强进行测量,使得测量结果具有较高的精度。这一结果对液晶器件的设计、制作和使用是有帮助的。     

液晶电控效应的实验研究

详细阐述了液晶的电光效应,介绍了利用分光光度计测量液晶透射比的方法。通过改变加在液晶盒上的电压大小及其频率高低,详细测量了液晶的透射比。通过做图分析了液晶的电控双折射效应,得出液晶的透射比随所加电压的大小和频率的高低而变化,以及液晶的阈值电压随频率的增高而减小的规律,这对液晶器件的设计与研究均具有一定的参考价值。     

向列相液晶层厚度的光学测量

液晶层的厚度对于液晶光阀的电光特性、响应时间等有重要影响。液晶层的标称厚度由介质垫圈决定。厚度测量的简便方法是测量液晶盒的空盒电容,从而求得盒厚。这样求得的是整个液晶盒中液晶层的平均厚度。我们采用光学干涉原理,对液晶空盒及各种取向的向列相液晶层厚度进行逐点精确测量。现将原理、     

一种新的测量扭曲向列相液晶盒盒厚和扭曲角的Stokes矢量法

提出了一种新的测量扭曲向列相液晶盒盒厚和扭曲角的Stokes矢量法。根据Jones矩阵推导出了Stokes矢量与液晶盒参数的关系,其原理是通过确定经过液晶盒之后偏振光的偏振特性来求解液晶盒盒厚和扭曲角。该方法在测量一个Stokes矢量时,在液晶盒后依次放两种波片,目的是改变经过液晶盒后的光的偏振态,再置一偏振分光棱镜分开水平Ip和垂直Is线偏振分量,测得两组光强,根据公式算得该Stokes矢量,从而求解液晶盒盒厚以及扭曲角。实验中我们用该方法测量了不同盒厚、扭曲角度的TN液晶盒。实验结果证明该方法可行,结果准确,并且可以测量盒厚较小的液晶盒。最后,我们理论分析了实验误差。     

TN型液晶双折射率的简易测量方法

为了实现一种简易的测量TN型液晶双折射率的方法,根据等厚干涉原理设计了一种楔形液晶盒。通过调节入射光的偏振方向而无需调整液晶分子取向实现寻常光（o光）和非寻常光（e光）,成功测量了液晶长轴方向和短轴方向的折射率。结果表明,本方法简单方便,能达到测量的基本要求。     

VA液晶显示器光程差测量方法分析

垂直排列Vertical Array简称VA,VA液晶显示器盒内液晶分子的排列方式是垂直排列,因此采用现有常用的光程差测试设备如CG-200,无法测量出VA液晶显示器的光程差。文章研究利用VA液晶显示器的显示机理,通过测试比较不同光程差对应的高压光电曲线,总结出测量VA液晶显示器光程差的简单方法。     

基于频谱傅里叶变换的平行光管液晶显示屏测透镜焦距研究

为了提高平行光管测透镜焦距的质量,采用频谱傅里叶变换和液晶显示屏方法.首先给出系统结构图以及测量方程;接着根据液晶显示屏上光斑位置变化的距离,鉴别出平行光管是否离焦,通过液晶显示屏最小像元尺寸计算最大检焦分辨率;然后基于频谱傅里叶变换对液晶显示屏定焦;最后给出了误差分析.实验测量显示液晶显示屏比目视法有更高的精度,测量重复性好.     

基于FPGA的液晶盒厚快速测量系统

在复杂的液晶显示器制造工艺中,液晶盒厚及其测量对液晶滴入量起着关键作用,进而影响液晶显示器件的底色及响应速度等光电特性.从光干涉原理出发,以FPGA为核心芯片,利用倾角传感器、光电传感器等模组设计了液晶盒厚快速测量系统,通过实验验证,系统具有误差小,设备简单,操作快捷等特点,满足液晶盒厚在线自动测量的同时,相对标准差提高到0.02％以上,充分满足了液晶显示器件生产厂家进行盒厚过程监控和液晶量准确计算的需要.     

液晶编码光栅编码设计与编码点匹配技术研究

物体形貌测量中,物体自身的特征信息往往较少,不足以实现三维重建,通过投射液晶编码光栅可以制造出足够的特征点,液晶编码光栅的编码设计及其精确匹配是形貌测量的关键技术。基于液晶显示可控的特性,由计算机控制实现液晶光栅编码的交换,无机械运动。通过液晶光栅编码可以直接获得被测物体形貌特征点信息,提高了测量速度和效率。实验表明,采用粗匹配和基于角点的精匹配方法,可以得到较高的测量精度,测量标准平板平面度测量误差为0．23mm。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first