类矩形保偏光纤应力双折射分析

ANALYSIS ON STRESS-INDUCING BIREFRINGENCE OF “PSEUDO-RECTANGLE” POLARIZATION-MAINTAINING OPTICAL FIBER

采用有限元方法对“类矩形”保偏光纤的应力双折射进行了分析,给出了保偏光纤横截面上的应力分布图形及应力双折射分布曲线;应用全矢量电磁场有限元方法,计算了保偏光纤的两个偏振模场的分布、传输常数及模式双折射.在给定模拟条件下,纤芯的应力双折射约为 3. 33×10-4,其模式双折射约为 3. 72×10-4.计算结果表明,这种“类矩形”保偏光纤与其它保偏光纤相比,有几个明显的优点,即有更佳的应力传递效果、均匀的应力场分布、更大的应力双折射.

The stress-inducing birefringence of the 'pseudo-rectangle' polarization-maintaining optical fiber (PMF) was analyzed by finite element method, and its stress distributions curve and stress birefringence distributions were presented. This fiber's polarization modes, transmitting constants and modal birefringence were computed by the full vector finite element method. The stress and modal birefringence is about 3.33 x 10(-4) and 3.72 x 10(-4) in simulation conditions, respectively. The results of computation demonstrate that the 'pseudo-rectangle' polarization-maintaining optical fiber has a number of obvious advantages with comparisons of the panda shaped fiber or the bow-tie shaped fiber: it is better in the stress transmitting effect, more uniform in the stress field distribution in fiber core and bigger in the stress-inducing birefringence.