客运专线信号监控系统研究

根据我国铁路客运专线管理信息化的模式,通过对客运专线信号系统特点的分析,提出客运专线信号监控系统的设计要求,设计了客运专线监控系统的方案及网络体系结构。     

Theoretical analysis of polarization properties for tilted fiber Bragg gratings

The polarization properties for tilted fiber Bragg gratings (TFBGs) are investigated theoretically based on coupled-mode theory and Mueller matrix method. The expression of wavelength-related polarizationdependent loss (PDL) for TFBGs with different tilt angles is derived and calculated. Simulation results are compared, and the results indicate that the polarization capability of TFBGs with 45° angle is stronger than other TFBGs with smaller angles. The degree of polarization for unpolarized light passing T...     

Simulation model of magneto-optic fiber Bragg gratings and its applications in Sagnac interferometers

According to the symmetry of transmission matrix for non-uniform magneto-optic fiber Bragg gratings (MFBGs),the simulation model of the non-uniform MFBGs with bidirectional injection of light has been presented for the Optisystem software.The simulation model is verified by comparing with the Matlab numeric results using the piecewise-uniform MFBG model.As an example,the polarization-dependent loss (PDL) of an MFBG-based Sagnac interferometer (MSI) is analyzed in detail.Simulation results indicate that the magnetic field sensitivity of the MSI system can be improved by optimizing the coupling coefficient of the coupler,and the maximum of peak PDL is up to three times that of the single MFBG structure.The simulation model proposed in the paper is useful for the design of MFBG-based optical information devices.     

个人隐私数据访问的许可证机制

本文提出了一种新的安全访问机制,称为个人数据许可证(PDL)机制,在此机制上,用户有权访问和修改其提供给Web站点的数据,同时,站点对用户数据的使用必须通过许可证的方式获得用户的授权。这种机制能保证用户数据不被非法滥用。     

PLC光分路器测试系统的设计与实现

针对PLC(Planar Lightwave Circuit平面波导)光分路器的参数测试,设计了一个快速测量该器件各项指标的测试系统,可测量的指标有插入损耗(IL)、回波损耗(RL)和偏振相关损耗(PDL)。辅以管理软件,可实现PLC光分路器的半自动测试,各项测试数据可形成报表储存和打印。     

Development of miniature optical fiber hybrid WDM coupler employing the FBT technology

An innovative technique for fabricating the optical fiber hybrid wavelength-division multiplexing (WDM) coupler is presented. The device is comprised of two components, a wavelength division multiplexer and an optical fiber coupler, in a miniature stainless steel tube. The outstanding features of the ultra-low polarization dependent loss (PDL) under 0.05 dB and the compact size of ∅3.5 × 65 mm for bare-fiber type of package are accomplished by using the pioneering methodology combining the main techniques of twisted and parallel fusion processes in the fused biconical taper (FBT) technology. Besides, its miniaturization is more competitive in both of the applications of optical communication and sensing systems where a compact-sized package is required for extending the flexibility of installation.     

集中抄表系统中的握手联络式串行通信协议

介绍了集中抄表系统中的握手联络方式的PC机与多单片机的串行通信设计方法,具有通信可靠性高的特点。并可应用于下位机并非一直处于接收就绪状态的场合,如实时控制、实时信号处理应用中。最后给出了通信协议及PDL语言的程序设计流程。     

光纤通信系统中偏振损耗对偏振态的影响

推导出具有偏振相关损耗(PDL)器件的Stokes模型,研究了光纤通信系统中PDL对光信号偏振态(SOP)的影响。数值模拟结果表明,入射信号光偏振度(DOP)小于1时,PDL对出射信号光的DOP和强度有直接影响;当入射光DOP等于1时,PDL对出射信号光的DOP没有影响,但随PDL的增加,出射光强度迅速减小,且信号光的SOP变化加剧。     

从个人数字图书馆的发展论高校图书馆在PDL构建中的角色

根据PDL研究主体、规模的不同对国内PDL发展阶段进行划分,在此基础上分析高校图书馆作为PDL构建能力的培养者、构建理论的研究者、构建优势的宣传者、缩小数字鸿沟的建设者等多重角色,以顺应数字化图书馆的发展和个性化信息服务的需求。     

初始啁啾和偏振效应对光纤通信系统的影响

采用多重重要抽样方法,对受偏振模色散(PMD)和偏振相关损耗(PDL)联合影响的10 Gbit/s光通信系统在不同脉冲初始啁啾和占空比下的性能进行了数值仿真.给出了PMD=10 ps和PDL=1、1.5 dB时开关键控(OOK)和差分相移键控(DPSK)调制的光传输系统的功率代价分布和系统失效概率.发现在不同占空比下,系统性能有明显不同;引入适当的初始啁啾(如啁啾因子C=0.5),有利于提高系统的性能.