数字视频光端机在电视现场直播中的运用

视频光端机长期运用在安防领域、道路监控系统中.分析数字视频光端机的原理,数字视频光端机的几个影响画面质量的指标如视频电平、带宽、信噪比等.根据高校的特点,介绍将视频光端机技术运用到电视现场直播中的做法和一些体会.     

FD-4250 140M光端机

本文系统介绍了 FD 42 5 0 140 M光端机的整体构成、工作原理及几项技术。     

新型防雷视频光端机研制及在航道监控系统中的应用

针对苏北运河航闸视频监控联网系统完全按防雷标准建设运行后视频光端机屡遭雷击损坏现象,从国标入手对防雷器及光端机防雷指标以及它们相互配合影响防雷效果的原因进行分析,研制了一种全新防雷视频光端机,解决了视频光端机防雷和联网汇聚问题。经实际运行巳证明防雷效果良好。     

五方会诊光端机市场多业务接入是发展方向

日前,记者试着“百度”了一下“光端机”,搜索到的相关内容大多是光端机厂商及产品介绍,而且数量之多足以点到你食指发麻。如果时光倒退几年,估计任何人也想象不到今天的光端机市场会出现如此“繁荣”的景象。我们不否认这种“繁荣”使得昔日高贵的光端机现在得以飞入寻常百姓家,然而,其背后却隐藏着一系列问题:品牌繁多,小企业泛滥,产品同质化严重,价格竞争愈演愈烈,而且不乏鱼目混珠的现象出现。为什么光端机市场会出现如此混乱的局面,市场出路在那里?《通讯世界》邀请了目前用户光端机领域内几家领先厂商的代表共同就用户光端机市场目前的现状及出路进行了深入地探讨。     

射频光端机的电磁兼容结构设计

从射频光端机的基本原理出发,通过对光端机的结构设计、材料选择以及腔体布局等几方面进行深入解析和软件仿真,很好地解决了射频光端机的电磁兼容问题,并给出了实际的测试数据。     

中美舰载光端机的比较

本文从光端机的结构，性能特性和环境适应性等几个方面就国产舰载光端机的质量现状与美国的同类产品进行了全面比较，并对国内该产品的进行了评述。     

IP网络视频监控前端接入解决方案的研究

文中分析了目前广泛使用的几种网络视频监控前端接入方案，即DVR＋光纤收发器、DVR＋光端机、视频服务器＋光纤收发器和视频服务器＋光端机，并针对各种方案指出了其不足之处，并提出了改进措施。     

CATV光纤传输系统设计及维护

ＣＡＴＶ光纤传输系统设计及维护马伟宪１５５０ｎｍ波长损耗０．２５ｄＢ／ｋｍ。目前的光端机发射接收波长主要是１３１０ｎｍ，但国际上正在开发１５５０ｎｍ的光端机，预计今年就可开发出满足超长距离传输需要，１５５０ｎｍ波长的ＡＭ光端机。在设计时，需要考虑光缆...     

关于砷化镓发光二极管的使用寿命初探

发光二极管是光端机的主要器件,其工作状态会直接影响光端机的多项主光纤传输效率。通过观察光机运行情况,统计发光二级管的工作电流值等有关数据,进行比较分析,试对发光二极管使用做一些探讨分析。     

市县HFC系统光端机的选择和使用

通过对两种光端机性价比的对比,阐述了网络工程中光端机的合理选择、选用原则以及光端机的使用、保养与维护。     

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.