高速OCDM系统中的全光阈值技术分析

Analysis of all optical thresholding technique in high speed OCDM system

分析了高速OCDM系统中基于非线性光学环境(NOLM)和非线性放大(NALM)环境的全光阈值技术。考虑了NOLM环境输入脉冲峰值功率对其阈值判决功能的影响,数值模拟了由高非线性光纤构成的NOLM和NALM环境的脉冲整形和旁瓣抑制功能,并和实验结果进行了比较。结果表明基于NOLM和NALM环境的全光阈值技术都能有效地抑制40 Gbit/s的OCDM系统中的干扰噪声,最优的NOLM环境的脉冲峰值输入功率为2 W,而NALM环境只需要mW量级的脉冲峰值输入功率即能够更好地抑制干扰噪声。

The nonlinear optical loop mirror （NOLM） and the nonlinear amplifying loop mirror （NALM） based optical thresholding in the high speed optical code division multiplexing （OCDM） system are analyzed. The input pulse peak power of the NOLM is optimized considering the thresholding decision function, pulse shaping and side-lobe suppressing of the NOLM and the NALM based on high nonlinear fiber are numerically simulated, and which is compared with experimental result. The results show that the interference noise in the 40 Gbit/s OCDM system could be suppressed effectively by the optical thresholding technique based on the NOLM and the NALM, and the system performance is improved.