一种基于双耦合器谐振环的梳状滤波器特性分析

为改善常规马赫-曾德尔(MZ)干涉仪型滤波器的输出特性,提出了一种由双耦合器和单模光纤构成的谐振环加人非平衡马赫-曾德尔干涉仪一臂中构成的新型梳状滤波器.推导了该器件的输出表达式,并进行了数值模拟.模拟结果表明,改进后的滤波器同时具有更宽的0.5 dB透过带宽和25 dB截止带宽,具有近似方波的输出谱,降低了系统对光源波长稳定性的要求,相对于常规的非平衡马赫-曾德尔干涉型滤波器来说,具有更好的滤波效果.最后分析了双耦合器谐振环上耦合器的耦合比以及环长度对该器件滤波性能的影响,给出了满足通信实用要求的各个参数的范围.

Analysis of Characteristics of the Interleaver Based on a Double-Coupler Resonator

In order to improve the transmission performance of the conventional Mach-Zehnder(MZ) interferometer,a novel interleaver based on MZ interferometer with a double-coupler and single mode fiber resonator in one arm is presented.The output expression is derived and numerical simulation is performed.The simulation indicates that the bandwidth of 0.5 dB passband and 25 dB stopband of proposed interleaver are simultaneously improved remarkably,which are much wider than those of the conventional MZ interferometer.The filtering performance of this proposed interleaver,which achieves a nearly square spectrum response,is much better than that of the conventional MZ.Influence on its transimission characteristics by the parameters caused by double-coupler resonator,coupling ratio and length of resonator,is also discussed,and the variations ranges of the parameters are also given for the communication requirements.