Analysis of Cascade Filter Characteristics with High Birefringence Fiber Loop Mirror
级联双折射光纤环镜滤波特性的分析

Cascade filter characteristics of high birefringence fiber loop mirror are studied theoretically,transmission power expressions of two kinds of series loop mirrors that connected with fiber optic isolator or not are given,and the filter characteristics of the two loop mirrors with different periodic ratio are numerically simulated and analyzed.There is no ralation ship between filter effect and the cascade sequence of two loop mirrors,and the filter effect is not affected by the fiber optic isolator which only increases the insertion loss.Different filter effect can be obtained by cascading and changing birefringence fiber's length ratio of two fiber loop mirrors.The general expression of transmission optical power for cascade high birefringence fiber loop mirrors is given,and different filter can be designed by analyzing the general expression theoretically.