不同几何结构电光偏转器比较研究

为了发展性能优良的电光偏转器,采用傍轴近似分析了级联棱镜电光偏转器的折射率梯度等效表达式,总结出了不同几何结构电光偏转器的偏转角和偏转轨迹公式,在此基础上比较研究了4种不同几何结构电光偏转器的偏转特性和偏转轨迹,比较分析了梯形、喇叭形和抛物线形几何结构电光偏转器的偏转灵敏度,为较大角度电光偏转系统的设计提供了有意义的参考。     

一种新型梯度电场控制光开关的原理研究

基于LiNbO3晶体的电光效应,提出一种利用外加梯度电场控制的新型1×2电光开关的设计理论.采用理论计算及有限元数值模拟的方法对晶体的电光偏转效果及其内部梯度电场的分布进行了分析,讨论了外加电场强度、晶体尺寸、电极条数等对光线偏转角度的影响.分析结果表明,外加梯度电场可以在LiNbO3晶体内部形成折射率的梯度变化,造成光线逐步偏转,且外加电场强度越大,电极条数越多,偏转角度越大.对尺寸为2 mm×2 mm×4 mm的LiNbO3晶体施加的外部电场最大值在1 kV/mm的量级时,光线总偏转角可达到2°(340 mrad)左右,有效地实现了1×2光开关的效果.     

近化学计量比LiTaO_3反转畴运动特性研究

通过添加助熔剂,生长了掺Mg近化学计量比LiTaO3(SLT)晶体,晶体的居里温度为684±1℃。对厚度1.8 mm的晶片进行外加单脉冲电场室温极化,得到了完全反转的畴结构。利用化学腐蚀的方法,观察极化过程中反转畴成核、运动及合并的过程。结果表明,室温极化时,反转畴的运动是非匀速的,实现完全反转至多需要50 s,极化初始阶段反转畴的平均横向扩展速率为0.012 mm/s。     

利用电光偏转器进行激光脉冲整形的两种扫描光路的比较

从理论上系统地比较了利用电光偏转器进行激光脉冲进形的两种扫描光路．并对两种扫描方式的优缺点进行了论述，指出了一种对空间扫描线复原精度的估计方法．为现阶段神光－Ⅱ升级的实验工作提供了理论基础．     

KNbO_3电光偏转器

分析了ＫＮｂＯ３晶体的电光性质，利用电光张量系数γ３３加工成电光偏转器，偏转梯度电场由四个柱面电极产生。实验结果表明，在结构参数、通光口径及其它条件均等同的情况下，该器件的基本品质因子约是ＬｉＮｂＯ３电光偏转器的２倍。     

新型可调电光偏转器

本文从理论上探讨了利用压电材料的电光效应来实现光束偏转的可能性,提出了电光偏转器的设计思想,指出电光晶体的最佳候选者为钨青铜型铌酸盐材料。     

电光学及其应用(续二) 第三讲 电光器件

1 引言利用电光效应可以制作出多种电光器件,它们在激光,光电子以及一些信息科学技术领域中占有重要地位,其中已得到广泛应用的当数电光调制器和电光偏转器,在这一章里,我们将以电光调制器和电光偏转器为重点讲述电光器件的工作原理以及一些设计上的问题。     

一种基于LTCC技术的UHF波段高性能带通滤波器

介绍了一种基于低温共烧陶瓷(LTCC)技术实现的UHF波段高性能带通滤波器,其中心频率为490MHz。由于该滤波器频率较低、波长较长,为了减小滤波器的尺寸,本设计采用了半集总半分布结构来实现。通过增加传输零点和滤波器级联技术大大提高了滤波器的带外抑制度。借助三维仿真软件进行优化仿真,设计出了一个中心频率为490MHz、带宽为100MHz、带外抑制优于40dB、尺寸仅为6.4mm×4.0mm×1.5mm的带通滤波器。实测结果与电磁仿真结果较为吻合。     

(Pb0.76Ca0.24)TiO3薄膜电畴反转行为的压电力显微镜研究

用溶胶-凝胶法在（Pt／Ti／SiO2/Si）衬底制备了（Pb0.76Ca0.24）TiO3（PCT）薄膜。利用扫描力显微镜（SFM）的压电响应模式（PFM）观测了PCT薄膜的纳米尺度畴结构。畴结构和晶粒尺寸相关,尺寸在100nm左右的晶粒表现为单畴,尺寸较大的晶粒表现为多畴。利用压电力显微镜研究了PCT薄膜中电畴的极化反转行为。通过SFM探针对畴施加一系列直流偏压极化,在每次极化后,利用压电响应模式扫描进行压电力成像,获得了与极化电压相关的畴反转信息。用探针施加电压对薄膜极化后,在不同的时间进行压电力成像,研究了电畴的退极化行为。     

彩色显像光栅枕形畸变的分析及校正（二）

消除光栅枕形畸变的技术措施目前消除光栅枕形几何畸变的技术措施主要有:利用垂直向偏转扫描锯齿波抛物电流调制水平向偏转扫描锯齿波电流,简称“偏转扫描电流调制消枕方式”,亦称“磁饱和消枕方式”偏转磁场场强分布形状消除光栅枕形几何畸变,简称“偏转场强分布消枕方式”;外加磁场消枕方式;多极场消枕方式;以及抑制彗形象差消枕方式等。     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

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