波长转换对光交叉连接节点中串扰的影响

针对具有波长转换功能的节点共享型和链路共享型光交叉连接(OXC)节点,分析了相干串扰和非相干串扰引起的功率代价并进行了仿真计算.结果表明,相干串扰引起的功率代价远远大于非相干串扰,尤其当时间延迟小于激光器的相干时间并小于码型周期时,串扰引起的功率代价最大.为达到一定的系统性能,分析了WDM光网络对器件的要求,并比较了波长转换器的加入对OXC节点串扰的影响,结果发现,加入波长转换器后,系统的功率代价有一定的改善,相同条件下波长转换器的加入对器件的隔离度要求降低2 dB.     

WDM全光网OXC节点串扰效应分析(续完)

4 OXC串扰参数变化的数值分析 下面将通过数值计算的方法对几种拓扑结构和器件参数进行分析评价.首先以串扰作为评价标准.     

WDM光网络中OXC结构对带内串扰积累的影响

串扰是波分复用(WDM)光网络中光交叉连接(OXC)投入实用的最大障碍。理论分析了基于扩展Benes(DB)结构和改进扩展Benes(GMDB)结构的3种典型OXC节点结构中的带内串扰,并数值模拟了基于两种结构的OXC节点中带内串扰的积累特性。结果表明,基于DB结构和GMDB结构的OXC节点可以完全消除低于二阶的各类串扰。发现基于GMDB结构的OXC节点能大大减少带内串扰的积累,与基于DB结构的OXC节点相比,基于GMDB结构的OXC节点对光开关串扰系数的要求放宽了5dB,说明OXC节点结构的选择对消除串扰尤为重要。     

多波长光交叉连接节点的优化设计

在WDM光网络中，光交叉连接（OXC）节点的串扰是限制网络规模的关键因素，提高光开关的隔离度是降低OXC串扰的一条途径，文章比较了3种不同结构的光开关矩阵的串扰特性，在此基础上对OXC节点进行了优化设计，改进后的OXC节点的串扰性能大的改善，网络规模也因此而得到了极大地扩展。     

光网络中的OXC研究

本文介绍了光交叉连接(OXC)节点在光网络中所处的位置,分析了透明OXC节点和非透明OXC节点两种结构的构成方式.同时分析了OXC节点的串扰性能和利用GMPLS协议实现OXC节点的控制方式.     

WDM全光网中OXC的串扰分析

本文以一个典型的光交叉连接(Optical Cross Connect,OXC)结构作为模型,对串扰的来源及其对信号输出功率的影响作了分析,并引入"功率代价"来衡量、比较相干串扰和非相干串扰对系统的影响;最后就如何改善系统的串扰提出了看法.     

硅PIN光电探测器阵列的串扰分析

在利用高密度线性阵列探测器成像时,探测阵列单元间的串扰将直接影响器件的成像质量.文章对厚度为100μm的背照式PIN光电探测器线性阵列的电串扰特性进行了分析,通过Silvaco TCAD器件仿真软件对阵列的暗电流和光电流进行了仿真,分析了像元间的电串扰特性,同时对比分析了保护环结构对器件的暗电流和电串扰特性的影响.仿真结果表明,保护环结构器件的暗电流和电串扰性能均优于无保护环的结构,在有保护环时PIN器件的串扰是无保护环结构的1/5.     

WDM光网络非相干串扰实验研究

在WDM光网络系统中,节点如OXC和OADM采用的光器件其非理想性积累构成系统串扰问题。本文提出了WDM光网络系统中串扰问题分析的一般数学模型,根据模型分析比较了WDM光网络中相干串扰和非相干串扰的区别。实验研究了不同非相干串扰代价条件下,对应WDM光网络系统的功率代价。对应1dB功率代价下,实验得出WDM光网络对应非相干串扰代价容限小于－20.8dB的结果。实验结果对于WDM光网络组网规划有一定的参考意义。     

光网络中大功率信号引起的带内串扰攻击研究

分析了光网络中大功率信号引起的带内串扰攻击,攻击信号功率和光开光串扰系数是带内串扰攻击对用户信号质量产生破坏影响的主要因素.在VPI仿真软件中搭建实验系统,以误码率为评价指标,定量研究了带内串扰攻击对用户信号质量的影响及其攻击传播能力.结果表明,当光开关串扰系数为-20 dB、初始攻击信号功率高于用户信号功率20 dB以上时,在OXC1处,经过第一级和第二级光开关的用户信号会受到攻击影响,经过第三级光开关的用户信号几乎不受攻击影响.带内串扰攻击具有一定的攻击传播能力,当初始攻击信号功率高于用户信号功率27dB、光开光串扰系数为-20 dB时,初始攻击信号的攻击能力可传播至OXC3,同时,二阶攻击信号基本不具备攻击传播能力.     

基于低串扰OXC的自动链路交换系统的设计与实现

介绍了基于低串扰OXC的自动链路交换系统的设计与实现,详细阐述了系统中OXC路由模块的硬件设计及实验方案.实验网络可以完成端到端光链路的自动建立.     

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.