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

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.