基于重构等效啁啾制作光纤光栅编解码器的光码分多址系统实现

在光码分多址(OCDMA)系统中，光纤布拉格光栅(FBG)编解码器是极具竞争力的核心器件，满足光接入网低成本、高性能的要求. 将重构等效啁啾 (REC) 技术制作的FBG作为编解码器运用于OCDMA系统. 实验采用一对511个码片、编码速率为6.4×10⁹/s的FBG编解码器，在编码匹配的情况下能恢复出输入信号，与编码非匹配的情况相比获得了8 dB的功率增益.这为REC技术制作的编解码光栅在OCDMA系统中的应用提供了实验依据. 关键词： 光纤布拉格光栅 光码分多址 重构等效啁啾 编解码器

Encoder and decoder of fiber Bragg gratings in optical code division multiple access system based on reconstruction-equivalent-chirp

Fiber Bragg grating (FBG) encoder-decoder is considered as one of the most competent coding components in optical code division multiple access (OCDMA) systems, and high-performance low-cost encoder_decoder is required for its wide application. With the same performance, the reconstruction-equivalent-chirp (REC) technique reduces the complexity of fabrication setup, in which only micron or sub-micron precision control is required in the fabricating process, instead of the nanometer precision of conventional super-structured FBGs (SSFBGs). In this paper, the principle of REC-based encoder_decoders is discussed, and 511 chip 6.4×10⁹/s encoder-decoders are fabricated. In order to quantitatively evaluate these encoder-decoders, the autocorrelation intensity peak to the maximum wing level ratio and the autocorrelation intensity peak to the maximum cross correlation level ratio are measured in OCDMA system. The experiment results show that these ratios achieved are above 8dB, which demonstrates the feasibility of the proposed encoder_decoders in practical OCDMA system application.