残余线双折射对于全光电流互感器工作点稳定性的影响

Influence of residual line birefringence on stability of operating point of fiber optics current transformer

保椭圆光纤中残余线双折射易受环境影响,导致光纤电流互感器(FOCT)性能易受环境影响。利用四元数方法,理论分析了因残余线双折射的存在,将导致全光纤电流互感器的工作点不稳定问题。结果表明,保椭圆光纤的圆双折射与残余线双折射之比RCL(圆/线比)的大小直接影响工作点的稳定性,总的趋势是随着RCL的增加,工作点越稳定。当RCL<2时,工作点极不稳定;当RCL>4后变得相对稳定。因此,参数RCL是一个衡量保椭圆光纤的重要指标,应在制作全光电流互感器前进行测定,确保FOCT的性能。

The residual line birefringence in the elliptic maintaining fiber is easily affected by the environment,so the performance of the Fiber Optics Current Transformer(FOCT)is easily affected by the environment.By using quaternion method,the problem of operating point instability of FOCT due to residual line birefringence is analyzed theoretically.The results show that the ratio of circular birefringence to residual line birefringence RCL(circular/line ratio)directly affects the stability of the operating point,and the general trend is that the operating point becomes more stable with RCL increasing.When RCL<2,the operating point is extremely unstable;on the other hand,when RCL>4 it becomes relatively stable.Therefore,the parameter RCL is an important specification to measure the elliptic maintaining fiber,and should be measured before making the FOCT to ensure the performance of FOCT.