光学 精密工程, 2008, 16 (9): 1608, 网络出版: 2010-02-28
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
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 optical communication Optical Code Division Multiple Access(OCDMA) Superstructure Fiber Bragg Grating(SSFBG) encoder/decoder correlation property
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。
Abstract
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 be less than 0.02 nm for the Gold sequences with length of 31 and chip duration of 6 ps at 1.555 μm.It is conclusion that a code can be used in different Bragg wavelengths to implement hybrid Wavelength Division Multiple(WDM) OCDMA system.
尹霄丽, 张琦, 余重秀, 刘小磊, 刘会师, 王宇. 相移超结构光纤布拉格光栅OCDMA编/解码器及其相关特性[J]. 光学 精密工程, 2008, 16(9): 1608. YIN Xiao-li, ZHANG Qi, YU Chong-xiu, LIU Xiao-lei, LIU Hui-shi, WANG Yu. OCDMA encoder/decoder based on phase shifted superstructure fiber Bragg grating and its correlation property[J]. Optics and Precision Engineering, 2008, 16(9): 1608.