多环光路结构光学电流传感头研究

增加环绕电流的光束环路数是提高法拉第效应光学电流传感器灵敏度的主要方法.本文介绍了利用正交双全反射保偏原理设计的双环路及多环路传感头结构,并对双环结构进行了实验测试.

点对点独立式光路切换保护的探讨与分析

随着光传输网络规模的不断扩大,对光纤通道的保护显得尤为重要。智能化光纤保护系统正是为了满足这一时代需求应运而生,它不但可以提供性价比合理的光保护系统,而且还具备强大的局端网管功能和快速自动控制倒换功能。文章简要介绍了光通信网络中独立式光路切换保护的一种方式以及它与传统环路及链路保护方式的区别,对关键性技术进行了分析与探讨。

基于距离自适应和有效共享路径感知的光疏导方法

针对灵活网格光网络中如何节约转发器与频谱资源的问题,该文研究了多点到多点组播业务的光路环路由机制,提出一种基于距离自适应和有效共享路径感知的光疏导方法。通过设计一种基于距离自适应的预处理机制,该疏导方法能根据业务成员节点的分布特点和距离自适应准则灵活地为业务构建光路环;在路由与频谱分配阶段,该疏导方法通过构造一个面向光疏导的业务决策矩阵和一个优先调度向量,将业务疏导到与当前业务具有有效共享路径最多的已路由业务上,并优先分配所需的频谱空间以提高光疏导的成功率,实现节约转发器与频谱资源的目的。仿真结果表明,该文提出的光疏导方法可以有效地减少业务消耗的转发器数目和子载波数目。

Night Vehicle Detection Using Variable Haar-Like Feature

This paper proposes a night-time vehicle detection method using variable Haar-like feature.The specific features of front vehicle cannot be obtained in road image at night-time because of light reflection and ambient light,and it is also difficult to define optimal brightness and color of rear lamp according to road conditions.In comparison,the difference of vehicle region and road surface is more robust for road illumination environment.Thus,we select the candidates of vehicles by analysing the difference,and verify the candidates using those brightness and complexity to detect vehicle correctly.The feature of brightness difference is detected using variable horizontal Haar-like mask according to vehicle size in the location of image.And the region occurring rapid change is selected as the candidate.The proposed method is evaluated by testing on the various real road conditions.

传感器

TM452.93 97042586实用化光学电流互感器=Practical optical currenttransducer[刊,中]/沈悦,刘延冰,易本顺(华中理工大学.湖北,武汉(430074))//电子测量与仪器学报.—1996,10(2).—36-40论述了光学电流互感器作为计量与保护用时,光路、电路的选择问题,由于温度、振动引起双折射,使光学电流互感器灵敏度变化以及如何克服等实际问题。图3参3(严寒)TP212 97042587多环光路结构光学电流传感头研究=Study of opticalcurrent transducers with dual-ring or mul-

All-optical buffer and shaper based on complex-modulated long-period-grating coupler and self-closed fiber loop

We propose a novel all-optical buffer and shaper based on the adjustable power transferring characteristics of the complex-modulated long-period-grating coupler(CM-LPGC)and the multiple circulations of the self-closed fiber loop.By turning on the external optical pumps,the signals can be stored by utilizing the nonreciprocal power transferring of the CM-LPGC.When the buffer time is satisfied,the signals can be extracted discretionarily by turning off the external optical pumps.In addition,by controlling the spectral bandwidth of the CM-LPGC,the temporal rectangular pulse can be obtained by re-shaping the Gaussian input signal.

Non-blocking four-port optical router based on thermooptic silicon microrings

By using silicon-on-insulator(SOI) platform, 12 channel waveguides, and four parallel-coupling one-microring resonator routing elements, a non-blocking four-port optical router is proposed. Structure design and optimization are performed on the routing elements at 1 550 nm. At drop state with a power consumption of 0 m W, the insertion loss of the drop port is less than 1.12 d B, and the crosstalk between the two output ports is less than-28 d B; at through state with a power consumption of 22 m W, the insertion loss of the through port is less than 0.45 d B, and the crosstalk between the two output ports is below-21 d B. Routing topology and function are demonstrated for the four-port optical router. The router can work at nine non-blocking routing states using the thermo-optic(TO) effect of silicon for tuning the resonance of each switching element. Detailed characterizations are presented, including output spectrum, insertion loss, and crosstalk. According to the analysis on all the data links of the router, the insertion loss is within the range of 0.13—3.36 d B, and the crosstalk is less than-19.46 d B. The router can meet the need of large-scale optical network-on-chip(ONo C).