相移超结构光纤布拉格光栅OCDMA编/解码器及其相关特性  

OCDMA encoder/decoder based on phase shifted superstructure fiber Bragg grating and its correlation property

作　　者：尹霄丽[1] 张琦[1] 余重秀[1] 刘小磊[1] 刘会师[1] 王宇[1] 

机构地区：[1]北京邮电大学电子工程学院光通信与光波技术教育部重点实验室,北京100876

出　　处：《光学精密工程》2008年第9期1608-1613,共6页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.60577045);教育部高等学校博士学科点基金资助项目(No.20050013002);电子科技大学宽带光纤传输与通信网技术教育部重点实验室开放课题资助项目

摘　　要：研究了基于相移超结构光纤布拉格光栅(SSFBG)的光码分多址(OCDMA)编/解码器的结构及实现双极性编/解码的原理。利用传输矩阵法仿真了器件的相关特性,推导了因光栅周期不同而导致的编/解码器之间布拉格波长偏差对器件相关特性的影响。结果表明,随着码字长度的增加,器件的相关特性得到改善;但是当保持码片间隔不变而增加码字长度时,编/解码器的相关特性对布拉格波长偏差更加敏感,对于长度为31的Gold序列,当码片间隔为6 ps,布拉格波长为1.555μm时,布拉格波长偏差<0.02 nm方可得到编/解码器之间良好的相关特性;这表明同一码字可以在不同的布拉格波长下重复使用,此特性有望用于波分复用(WDM)型OCDMA系统中。Based on phase Shifted Superstructure Fiber Bragg Grating （SSFBG）, the structure and bipolar encoding/decoding principles of an Optical Code Division Multiple Access （OCDMA） system were researched and its correlation property was simulated by transmission matrix method. The effect of Bragg wavelength deviation due to the mismatch of the grating period between encoder and decoder on correlation property was analyzed theoretically. The results indicate that the correlation property is improved with the increasing of code length, but it is more sensitive to the deviation of Bragg wavelength between encoder and decoder when the code length is increased and the chip pulse width is fixed. To obtain desired correlation property, the deviation of Bragg wavelength between encoder and decoder must he less than 0.02 nm for the Gold sequences with length of 31 and chip duration of 6 ps at 1. 555μm. It is conclusion that a code can be used in different Bragg wavelengths to implement hybrid Wavelength Division Multiple （WDM） OCDMA system.

关 键 词：光通信 光码分多址 超结构光纤布拉格光栅 编/解码器相关特性 

分 类 号：TN929.11[电子电信—通信与信息系统] TN253[电子电信—信息与通信工程]