DWDM可重构光网络试验床及其监控管理

 本文设计集成并演示了一种业务驱动型可重构光网络平台,建立了光网络的固定连接和交换连接,探讨了可变业务网络的可重构流量疏导中的完全适配方案的实现方法,根据业务流量变化的需求,实现了光网络物理结构的重构.根据可重构光网络管理的特殊要求,实现了对该光网络中光网元控制管理和各光波长通道波长稳定性、光信噪比、信道功率、定时抖动、消光比、色散、误码率等性能参数的监控,且该光性能监控方案对数字光信号的协议和速率透明,还解决了动态路由技术条件下实时光功率电平的均衡问题.     

光开关矩阵技术及其应用研究

光开关矩阵是智能光交叉连接设备和可重构光分插复用器核心技术,是构建自动交换光网络的基础.文章介绍了大规模商用的光开关矩阵的关键技术及其进展,详细分析了光开关矩阵在自动交换光网络中的应用.     

光开关矩阵在自动交换光网络中的应用

自动光交换网络是光网络的发展趋势,其核心技术是光开关矩阵。光开关矩阵是智能光交叉连接设备和可重构光分插复用器核心技术,是构建自动交换光网络的基础。主要介绍了大规模商用的光开关矩阵的技术特点及其在自动交换光网络中的应用。     

可调谐光滤波器的发展及其DWDM应用

可调谐光滤波器是未来全光网络中的核心光器件,在DWDM系统中发挥着重要的作用.对几种常用并极具发展潜力的可调谐光滤波器的工作原理、结构、性能以及最新进展分别进行了介绍,指出了各自的功能和缺陷.最后给出了可调谐光滤波器在可重构光分叉复用和光性能监测方面的应用.     

制约OTN启用光层ASON因素浅析

随着支持灵活调度波长的ROADM(Reconfigurable Optical Add/Drop Multiplexer,可重构的光分插复用设备)设备在光传送网络中的广泛应用,使得OTN网络启用光层ASON成为了可能,本文针对目前制约上海本地OTN网络启用光层ASON的关键问题进行逐一分析,并提出相应的解决方案.     

基于光子晶体可重构光分插复用器的设计

可重构光分插复用器(ROADM)可实现光网络的动态重构,是光网络的重要器件。设计了一种基于二维光子晶体的可重构光分插复用器。该分插复用器采用点、线缺陷结构,在点缺陷中填充非线性介质,不同大小的点缺陷放置在线缺陷侧面的相应位置。根据耦合模理论,当没有外界激励光时,入射光波与点缺陷发生耦合;当有外界激励光时,入射光波与点缺陷不发生耦合,实现波长重构。仿真结果表明:当信道间隔为20nm时,该器件具有体积小、上/下载效率高、消光比高、响应时间快等优点。     

光开关矩阵技术及其性能分析

光开关矩阵是智能光交叉连接设备和可重构光分插复用器核心技术,是构建自动交换光网络的基础。本文主要介绍了大规模商用的光开关矩阵的关键技术原理,并且详细分析了由技术原理所决定的性能指标。     

IP over WDM光网络的演进趋势

由于IP业务的指数增长以及WDM在传送网中的主导地位,将IP业务直接承载于WDM系统的IP ver DM光网络成为理想的选择。IP over WDM光网络可分为三个阶段,即：点到点IPoverWDM、IP0ver可重构WDM、IPover光交换的WDM。     

动态可重构的智能光载无线接入技术

文章认为动态可重构的智能光载无线网络可以融合光纤和无线接入系统,通过引入新的网络架构、媒体访问控制(MAC)协议、系统链路以及关键器件等系列新技术,满足通信网对高效、宽带以及灵活等特性的需求。基于动态可重构的智能光载无线技术,文章在网络层提出适合智能光载无线技术的网络架构;在MAC层提出使光载无线MAC层的性能得到提升、保障联合资源的动态可管控的专用设计;在系统层提出在光域对射频信号进行处理、传输与控制的相关技术。文章还在器件方面提出利用特殊结构改善滤波、天线等性能的新技术。     

采用光码分多址技术的高速计算机局域网

本文提出一种可行的适于高速计算机网络的光码分多址技术，该网络采用光正交码和光信号处理，以保证实时数据通信。提出的全光结构的快速可调光正交码编码器和解码器，可在光域中用电光开关和光延迟线实现，能支持超高速吞吐量且重构时间很短     

Calibration of optical modulators by optical down-conversion

A new method for the calibration of intensity modulators and modulated laser diodes at millimeter-wave frequencies is presented. The method uses an integrated-optic modulator as both a mixer and a frequency doubler. To demonstrate the measurement technique an intensity modulator is calibrated over the band 26.5-40 GHz. The measurement system employs no components exceeding 20 GHz (excluding the RF generator), and with relatively minor modifications measurements in excess of 60 GHz are feasible     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlington circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitiyity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

Low-noise optical receiver for high-speed optical transmission

This paper describes the design of a low-noise optical receiver using Si bipolar transistors for high-speed optical transmission. The conventional common emitter-common collector circuit (CE-CC pair) and Darlingtou circuit (transimpedance amplifiers with parallel feedback) are studied. Optimal CE-CC pair collector-biasing current for attaining minimum noise current with a 400-MHz bandwidth is 2.7 mA, and less than 1.2 mA for the Darlington circuit. It is confirmed that the Darlington circuit is better than the CE-CC pair in signal-to-noise ratio by about 1.5 dB. The low-noise Darlington optical receiver with a Ge-avalanche photodiode has achieved an optical sensitivity of -41 dBm for a 400 Mbit/s RZ pulse with a bit error rate of 10^-10. This is a 2.5-dB improvement in optical sensitivity over that of the conventional CE-CC receiver.     

Coherent optical tapping using semiconductor optical amplifier

Semiconductor optical amplifiers are attractive not only as optical repeaters but also as functional devices, since carrier density modulation in amplifiers causes a nonlinear phenomenon. Utilizing the effect of the carrier density modulation on the semiconductor optical amplifier junction voltage, a coherent optical tapping is proposed for signal monitoring or control signal extraction. A 155 Mb/s FSK (frequency shift keying) signal tapping was realized with a simple configuration using heterodyne single-filter detection with -24.4 dBm sensitivity. Many applications for this coherent optical tapping are discussed, and basic characteristics for frequency-selective tapping from FDM (frequency division multiplexing) signals and optical amplifier gain control are examined     

利用光学微分预处理的强度光学相关

本文把采用菲涅耳全息滤波器的强度光学相关识别系统与光学微分预处理系统相结合,通过对输入图像进行边缘增强预处理,强度相关器的鉴别能力得到了改善。给出了理论分析和实验演示的结果。     

Nonlinear optical glasses for ultrafast optical switches

In this paper we report degenerate four-wave-mixing measurements of the nonlinear coefficient of rutile and a number of optical glasses at 1.06 μm. We define a figure of merit which measures the suitability of a material for nonlinear waveguide switches and show that the best glasses have figures of merit substantially higher than any other material. We include a brief discussion of the types of switching elements that could be made with these materials.     

光交叉连接器的光传输中的应用

目前以IP业务为代表的数据业务爆炸式增长,单信道传送速率从2.5Gb/s到10Gb/s到40Gb/s的快速增长,密集波分复用技术的使用,骨干网的电信级大容量快速交换需求,使得对光传送网交换节点的要求越来越高.网络的生存性、网络的恢复和自愈问题都变得非常重要.光交叉连接器(OXC)技术的发展,替代了复杂昂贵的电交叉连接,使空闲光纤数减少.同时,不需要光电转换,提供了比电交叉连接更高的交换效率.OXC能在光层解决网络恢复和自愈问题,极大地提高了网络的生存性和恢复速度.因此,光交叉连接器作为光传送网的关键设备,它的发展将对光传送网起到重大的推动作用.     

光开关玻璃的飞秒光学开关特性

通过在碲玻璃中添加重金属离子,尝试制作了具有较大的非线性折射率、时间响应快、吸收小的光开关玻璃。采用超快飞秒光克尔门技术对光开关玻璃的光克尔信号进行测试,测试结果显示,光开关玻璃的光克尔信号对称性好,信号半高宽度达到~225 fs,三阶非线性极化率达到~0.810-20 m2/V2,透过率达到70%~80%;研制的光开关玻璃为皮秒和飞秒光开光材料的选取提供了依据。     

集成光学声光光通道监测仪的研究

在集成声光可调谐滤波器(IAOTF)的基础上,提出了一种新型的集成光学波导型声光光通道监测仪(OCM).介绍了该OCM的工作原理及其基本结构,对它的插入损耗、响应时间、波长范围、波长分辨率和波长精度等性能指标进行了分析与计算,并对制成的集成光学声光OCM进行了实验研究.理论分析和实验结果表明,该OCM能够对密集波分复用(DWDM)系统多路光信道的工作波长和功率同时进行监测,其插入损耗小于3 dB,响应时间小于7μs,波长监测范嗣达174 nm,波长分辨率可达0.3 nm、波长精度可达±30 pm.     

Fusion splicing between optical circuits and optical fibres

Splicing between an optical fibre and a planar deposited silica waveguide was performed by using a CO2 laser as a heat source. The average splicing loss of 30 samples between a multimode graded-index fibre and a deposited silica waveguide was 0.18 dB. Reflection from the joining point disappeared by the fusion splicing.