基于光纤光栅技术的新型光子器件及其在动态可配置波分复用光网络中的应用

报道了光纤光栅外腔激光器、基于可调谐光纤光栅的动态可配置分插复用器(OADM)和全光波长转换器等在全光通信网中有应用潜力的新型光子学器件的实验结果，演示了这些器件的功能，基于这些器件建立了4路符合ITU—T波长标准，间隔为1．6nm的具有动态波长路由、全光波长转换及光信号实时监控功能的密集波分复用光网络演示系统。     

波长路由在并行计算机光互连中的应用

提出了一种波长路由并行光互连技术，其路由直接在源端用目标地址选择波长来建立，各波长有独立传输路径并采用光通道复用，路由变换节点为全光结构，光信号在变换节点处无转发延迟。此技术可应用于并行计算机互连网络和分布式高性能计算机群的互连网络。     

光开关转换时间测试仪的研制

作为自动交换光网络中的核心器件，光开关将在未来全光网中发挥着重要作用，并成为未来光联网的关键技术准确测量光开关的转换时间为其应用在不同领域提供了参考。     

光分插复用器的设计原则与功能实现

光分插复用器(OADM)是光传送网中的重要网元。本文提出了一种OADM的设计原则与实现方法，讨论了实现OADM中的状态检测、功率均衡、自动保护倒换等关键技术问题及相应的解决方法，并给出了利用OADM进行长距离传输与组网的实验研究结果。结果表明，我们研制成功的OADM具有先进性、实用性和可靠性，现已成功地应用于中国高速信息示范网(CAINONet)中。     

一种新型IP OVER WDM城域网的节点结构

提出了一种基于波分复用（WDM）,分组交换,副载波复用和波长变换技术的新型全光城域网节点结构,网络拓扑采用环形,网络节点采用可调输出固定输入的选波原则以利于数据的多重接入,副载波复用和基于级联半导体光放大器的波长变换,实现了射频副载波路由信息与基带IP数据包的同步复用和IP数据包的透明传输。     

光开关转换时间测试仪的研制

作为自动交换光网络中的核心器件,光开关将在未来全光网中发挥着重要作用,并成为未来光联网的关键技术。准确测量光开关的转换时间为其应用在不同领域提供了参考。     

MEMS光开关应用于机群系统光互连网络

建立了千兆位传输结构的高性能光互连网络 ,以提高计算机机群系统的网络性能 .利用MEMS 4× 4光开关和具有硬件路由功能的光互连网络PCI总线接口卡构成光互连链路 .光信号传输速率达 1Gbits/s以上 .基于MEMS的全光无堵塞光开关减少了光 电转换 ,开关方式与光信号的波长、速率和数据格式无关 .利用这种网络结构 ,可以最大限度地减少网络延迟和网络通信开销 ,提升了机群系统的总体性能 .利用MEMS 8× 8光开关设计了星型环型混合拓扑的光互连网络 .采用了具有硬件路由功能的光互连网络接口卡 ,并以Ethernet为控制网络实现了对MEMS光开光的动态配置 .分析并测试了光互连网络的通信性能 :峰值数据传输率可达 1Gbits/s ;数据量在 3Mbytes以上时 ,网络整体性能明显提高     

应用于全光网络的取样布拉格光纤光栅Interleaver设计

基于取样光纤布拉格光栅(SFBG)的光Interleaver能将一路光信号解复用为两路奇偶波长信号,具有插入损耗低、各信道反射率均匀和低色散等优点,特别适用于未来全光DWDM中波长复用/解复用、插入/分离。为此介绍了取样光栅Interleaver的基本设计理论,给出了设计实例,对取样光栅Interleaver等光器件的实用化有一定的参考意义。     

基于AWG实现OADM实验研究

设计了基于位相波导光栅（AWG）的复用和解复用双重功能的两种OADM网元实现方案,分析并实验研究了两种OADM网元的串扰特性。结果表明,采用一定结构设计的OADM网元可以较好地减小串扰影响。     

新型光开光的研究及其在光网络中的应用

针对DWDM光网络的核心器件以及影响光网络性能的主要因素之一的光开关，概述了共目前的各种技术，尤其分析了目前比较成熟，性能比较良好的热光开关和微机械光开关的原理和性能，并对其在光网络中的应用进行了分析。     

Symmetric operating point for increasing the extinction ratio of semiconductor based optical loop mirrors

Terahertz optical asymmetric demultiplexors (TOADs) use a semiconductor optical amplifier in an interferometer to create an all-optical switch and have potential uses in many optical networking applications. Here we demonstrate and compare experimentally a novel and simple method of dramatically increasing the extinction ratio of the device using a symmetrical configuration as compared to a ‘traditional’ configuration. The new configuration is designed to suppress the occurrence of self-switching in the device thus allowing signal pulses to be used at higher power levels. Using the proposed configuration an increase in extinction ratio of 10 dB has been measured on the transmitted port whilst benefiting from an improved input signal power handling capability.     

Mach-Zehnder电光调制器产生多波长光源的实验研究

随着对光纤通信容量需求的不断增长,DWDM系统和L波段光器件成为当今研究的热点,多波长光源作为重要的有源器件倍受青睐。本文研究了基于Mach-Zehnder结构的电光强度调制器的理论模型,利用公式仿真得到在一定微波功率调制下强度调制器输出的扩频光谱。实验研究了M-Z结构的集成电光波导强度调制器光波长1550nm处10GHz、15GHz、20GHz扩频的实现,对理论分析所得的输出光谱与实际系统的输出光谱进行比较,发现谱线情况较一致。在调制频率10GHz,调制深度C=1.39,V=2.98V时,输出光谱中可清楚观察到正负三阶等频率间隔的边波带,尤其是一阶边波带与中心波长峰值功率几乎相等,可实现三路光源等功率输出。     

Large size optical windows for superfluid helium applications

We report on a technique to seal large size optical windows on metal cryostats for He II applications.     

Coating uniformity improvement for a dense-wavelength-division-multiplexing filter by use of the etching effect

The uniformity of optical narrow-bandpass filters for dense wavelength division multiplexing (DWDM) has been improved by control of the coating parameters of electron guns and the ion source. The optical film was deposited by the electron gun and was etched by the ion source during the ion-assisted deposition process. The uniformity of the coating of a 100 GHz DWDM filter is better than +/- 0.003% over a circular area of 50 mm in diameter when such an etching process is used.     

非球面光学元件的制造技术(英文)

非球面光学元件广泛用于不同领域,但它们的成功应用主要取决于其质量和制造费用。近几年来,通过开发计算机数控光学加工机械和新的制造技术,已经取得了大的进展。本文涉及制作非球面所用的主要技术。总结将指明适合的用途和这些方法中的每一项的技术成就。两个实际的例子表明非球面光学元件的挑战和光明未来。     

Effect of stress on performance of dense wavelength division multiplexing filters: optical properties

Thin-film filters used for dense wavelength division multiplexing (DWDM) applications are processed by a variety of deposition techniques, including ion-beam sputtering. Ion-beam sputtering produces high-quality coatings and provides flexibility of coating materials. However, DWDM filters consisting of oxide films that are reactively deposited by ion-beam sputtering, as in most sputter techniques, typically exhibit high levels of compressive stress. This affects the optical characteristics of the filters. Details of the filter passband characteristics and wave-front distortion illustrate the influence of the stress. Spatial variation of the stress on the filter surface causes the filter center wavelength to have spatial variation, and it causes the filter to have an asymmetric passband characteristic.     

Influence of monitor passband width on the layer thickness determination during deposition of a dense-wavelength-division-multiplexing filter

The monitor passband width of an optical monitor is an important parameter for the fabrication of a dense-wavelength-division-multiplexing (DWDM) filter. The peak insertion loss and transmittance of one-cavity narrow-bandpass filters (NBPFs) were analyzed by using different passband widths. The simulation monitoring curves of the last layer of the first, second, third, and fourth cavities of a five-cavity DWDM filter with different monitor passband widths were investigated. The last layer of each cavity is very sensitive to the monitor passband width, showing that the monitor passband width of an optical monitor should be less than half the designed passband width. This analysis demonstrates the successful fabrication of a five-cavity DWDM filter.     

一种大容量的二维光正交码

首先构造一种扩展的立方线性同余码（ECLC）并分析了其码字性能。在此基础上，用该码作为时间扩频伪随机序列和以素数码（PC）作为跳波长伪随机序列。再构成一种新的二维光正交码ECLC/PC，然后分析了ECLC/PC码字的性能，并与EQC/PC作为比较，相比之下，两者的码长和码重都相等，前者的互相关性能略有下降。但码字容量大大增加。因此，ECLC/PC适合于接入用户数较多的OCDMA系统。