光纤通信技术讲座--(九):光复用技术

介绍波分复用(WDM)、光时分复用(OTDM)和光码分复用(OCDM)的原理.     

基于WDM和OCDM光分组交换网络研究

光码分复用(Optical Code Division Multiplexing,OCDM)在光域对信号进行编码和解码,对用户数据进行全光信号处理,是实现真正意义上的全光通信最有希望的复用技术之一。把OCDM技术和波分复用(Wavelength Division Multiplexing,WDM)用于光分组交换(Optical Packet Switching,OPS),能给网络带来许多优点。本文介绍了一种新型的基于WDM和OCDM的光分组交换系统,及扩展了系统用户容量又避免了对信号的进行电域处理,实现全光交换。     

基于OCDM光码标签路由信息并行处理的研究

基于OCDM(光码分复用)技术和MPLS(多协议标签交换)技术,采用分离编解码方案对可并行光码标签路由技术进行研究.利用光极性特性实现标签与净荷的分离,采用FBG(光纤布拉格光栅)编码器对数据进行编解码.由于系统采用码分复用,允许不同净荷在时间上重叠,同一波长的OCDM标签路径在核心路由器中并行处理,提高了系统的吞吐量...     

用于光码分复用通信系统的编解码器

介绍了光码分复用(OCDM)通信系统的编解码器,包括光振幅、相位、频域和可调谐OCDM编解码器等,并在各种编解码器特点、结构、成本和发展前景等方面进行了比较分析。     

基于OCDM的PON监控技术研究

讨论了OCDM在无源光网络监控系统中的应用,介绍了基于OCDM的1D码、周期码方案及其监控原理。分析了两种监控方案中误码率与用户数、误码率与门限值的关系。仿真结果表明,与1D码相比,周期码具有更好的码字特性,更能满足当前PON监控系统多用户、高信噪比的要求。     

一种基于OCDM 的新型雷达通信一体化系统

为提高频谱利用率并实现系统小型化、集成化,近年来雷达通信一体化系统成为重要研究方向。正 交线性调频波分复用(OCDM)信号是利用菲涅尔变换形成的一组正交线性啁啾(chirp)信号,基于OCDM 的雷达通 信一体化信号不仅具有正交频分复用(OFDM)信号的频谱利用率高、适合高速数据传输等优点,且具有更好的抗多 径干扰能力,被认为是较好的OFDM 一体化信号替代方案。文中提出了一种新型OCDM 雷达信号处理方法,有效去 除随机通信数据的同时,大幅降低计算复杂度。基于此方法,进一步构建了新型OCDM 雷达通信一体化系统,分析 比较了多径信道下,OCDM 系统与OFDM 系统的通信性能,并仿真比较了OFDM 系统、传统OCDM 系统以及新型OCDM 系统的雷达性能。结果表明,新型OCDM 一体化系统的通信性能优于OFDM 系统,在大幅度降低传统OCDM 系 统的雷达信号处理算法计算复杂度的同时,具有更好的雷达探测性能,整体方案具有良好的工程应用前景。     

基于OCDM混合1D/2D码的PON监控系统分析

主要讨论基于OCDM混合1D/2D码在PON监控系统中的使用及整体模型,该模型是在1D码、2D码基础上提出的,是1D码和2D码的结合体。利用混合1D/2D码技术对不同的用户分配不同的码字,以实现多用户、高信噪比的实时监控。     

基于OCDM的PON监控编码技术分析

鉴于OCDM的PON监控技术在多用户和实时监控方面的优越性,提出多种编码方案.主要介绍基于OCDM的PON监控技术的1D码、2D码、1D/2D混合码以及周期码的基本原理,并研究分析各种编码方案在监控性能上的优缺点.     

基于GMPLS的新型二维标记交换网络的研究

对MPλS进行扩展,提出基于GMPLS的新型二维标记交换(MPCλS:Multi-Protocol Code-λ Switching),利用光码分复用(OCDM)结合MPλS对数据进行复合多维度的标记交换,降低了所需波长数;给出网络拓扑发现和复合LSP的建立过程算法,实现资源的灵活配置;引入通用成帧规程(GFP),并对其进行扩展改进,实现对新型二维标记交换网络的流量整形.     

双选信道下OCDM系统低复杂度均衡

正交Chirp复用(OCDM)是近年来提出的一种新的多载波体系,通过菲涅尔变换,获得一组正交Chirp信号,实现了CSS的最大频谱效率。该文介绍了OCDM系统的基本原理,重点研究了OCDM系统的低复杂度均衡算法。双选信道下,传统的MMSE均衡算法性能下降,提出一种基于近似带状矩阵的阻尼LSQR算法,作为求解稀疏矩阵的最小二乘迭代算法。为了缓解快速时变信道中的ICI,提出一种基于近似带状矩阵的LSQR-BDFE算法,结合判决反馈均衡,通过LSQR算法迭代计算。仿真结果表明,双选信道下,OCDM系统比OFDM系统有着更好的BER性能,所提出的LSQR-BDFE算法和带状阻尼LSQR算法,比MMSE均衡算法有着性能优势。     

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