为了改善全光纤马赫-曾德尔干涉仪(MZI)型梳状滤波器 (interleaver)的输出特性，提出了由一个 2×2光纤耦合器和一个带自反馈光纤谐振腔的光纤耦合器级联组成的改善型的全光纤 MZI型梳状滤波器。根据其结构，利用光纤传输理论和矩阵理论推导出了该器件的输出表达式，并进行了数值模拟分析。结果表明：该器件在合理参数的情况下，利用带自反馈光纤谐振腔引入的相位调节效应，使其 25 dB截止带宽为 46.7 GHz，约占 50 GHz频率间隔的 93.4%，输出光谱形态近似于方波。当存在传输损耗时，两束干涉光信号的幅度不存在明显的差异，降低了传输损耗对滤波器消光特性的影响，与传统的光纤谐振环辅助非平衡 MZI型梳状滤波器相比，不仅降低了传输损耗对滤波器消光特性的影响，而且还将所需的光纤耦合器数目减少至 2个，使其在未来的密集波分复用系统中能发挥重要作用。

In order to improve the transmission performance of all-fiber Mach-Zehnder interferometer (MZI), a novel all-fiber MZI interleaver is proposed and discussed in this paper. All-fiber interleaver consists of one 2×2 fiber coupler and one coupler with self-feedback fiber ring resonator. According to its structure, the output expression of the device is deduced by using optical fiber transmission theory and matrix theory, and numerical simulation analysis is per-formed. The results show that the device adopts the phase adjustment effect introduced by the self-feedback optical fiber resonator with reasonable parameters, and its 25 dB cutoff bandwidth is 46.7 GHz which accounts for 93.4% of the 50 GHz frequency interval. The output spectrum is similar to the square wave output. This device requires 2 fiber couplers, which is less than the number of couplers needed for the conventional all-fiber MZI-interleaver. When considering the existence of transmission loss, there is no difference in the amplitude of the two interference optical signals, which reduces the influence of transmission loss on the extinction characteristics of the filter. Compared with the conventional unbalanced MZI type interleaver with an optical fiber resonant ring, the structure is simple and compact, and has a certain anti-deviation ability. It also reduces the difficulty of making the device, which makes it play an important role in the future of dense wavelength division multiplexing systems.