为了实现具有全光纤结构和波长可选择滤波器，设计并从理论上计算和分析了一种基于双折射光纤的干涉滤波器。该滤波器具有很好的选频特性，不同的偏振角自由组合使得该滤波器具有更灵活的调节性。该滤波器提高了双折射光纤的使用效率，用12m高双折射光纤可以产生等同于在Sagnac环形腔中用16m同样光纤时的滤波效果。这种高效波长可选择滤波器还具有较好的光频隔离效果，并很容易用光纤或光波导制作出来。

Filter is an indispensable component for optical fiber communication system, especially for filter with all-fiber structure and selectable wavelength spacing due to its unique characteristics. A novel periodic filter with interleaving wavelengths based on high birefringence fiber interferometer was proposed and theoretically analyzed. Simulation results indicate that this filter has unique features. By adjusting the combination of the polarization rotations in this comb filter, filtering channels can be chosen by suppressing interleaving channels. The efficiency of the birefringence fiber is enhanced, as using 12m high birefringence fiber can obtain the same filtering results with using 16m birefringence fiber in the Sagnac filter. This filter has potential applications for multi-wavelength fiber laser and other optical fiber communication system.