采用弹性力学理论和复变函数法导出了熊猫型保偏光纤应力双折射的近似解析表达式.利用有限元法数值分析了熊猫型保偏光纤的双折射特性,结果表明,与采用纤芯中心应力相比,采用芯区平均应力表示光纤的双折射较为精确,且结果与解析法导出的芯区中心应力双折射计算结果相比误差小于0.18%.在此基础上进一步分析了应力区失配对熊猫型保偏光纤的双折射所产生的影响,并通过实验测试证明了分析结果的正确性.
An approximate analytical expression of the stress birefringence for Panda polarization-maintaining fiber(Panda-PMF) was deduced by using elasticity theory and complex function method.Based on this expression,the birefringence properties of this fiber were analyzed numerically by using the finite-element method.The results show that the birefringence expressed by core average stress mode is more accurate than that expressed by the core center stress mode and the error of the former is less than 0.18% compared with that of the analytic method.Further more,the birefringence degradation of the Panda-PMF induced by stress area mismatch was analyzed and proved by the related experiment.