一种新结构MZI型全光纤Interleaver的理论分析

Theoretical analysis of a novel all-fiber interleaver by using improved Maeh-Zehnder interferometer

根据光纤谐振腔反馈回路对光信号引入的相位调节原理,借助一字型3×3光纤耦合器构建的带自反馈光纤谐振腔的2×2光纤耦合器,提出了一种新结构的全光纤马赫-曾德尔干涉仪(MachZehnder interferometer,MZI)。推导了该MZI的输出表达式,并对它作为波长交错滤波器(Interleaver)时的滤波性能进行了数值模拟分析。分析结果表明,与传统的全光纤MZI-Interleaver相比较,它的滤波性能可以得到明显改善,其透射率形态更加接近于方波,阻带抑制和过渡带滚降特性明显加强。

According to the phase modification provided by the fiber ring resonator, a novel all-fiber Mach- Zehnder interferometer （MZI） is proposed. This improved MZI is composed of a fiber ring resonator and a 2 ×2 single fiber coupler. The fiber ring resonator with 2 × 2 input and output ports with a self-feed- back loop is based on a collinear 3×3 fiber coupler,and it is used as input device of the MZI. The trans- fer function of the MZI is derived. The filter characteristics of the MZI,whieh is used as all-fiber MZI-interleaver,are analyzed by numerical simulation. The analysis results show that, compared with conven- tional all-fiber MZI-interleavers, the output waveforms of proposed interleaver are more close to a nearly square spectrum response, the isolation in stopband, the rolloff in transition band, the bandwidth of pass- band and stophand of proposed interleaver are simultaneously improved remarkably.