为了减小保偏延迟光纤偏振串音对光纤电流传感器测量精度的影响, 利用琼斯矩阵研究了全光纤电流传感器的偏振耦合误差。简化了保偏延迟光纤的偏振串音模型, 并基于简化模型得出了保偏延迟光纤偏振串音与输出的关系。通过理论仿真分别分析了在常温和变温条件下偏振串音对传感器变比的影响。对比实验结果与理论分析结论, 验证了简化的偏振串音模型的合理性和仿真结果的正确性。测量了实际保偏延迟光纤偏振串音的温度特性, 结果表明: 在延迟光纤存在一定偏振串音时, 光纤电流传感器的变比误差随电流的增加而增大;电流一定时, 延迟光纤串音越高, 光纤电流传感器的变比误差越大。最后, 给出了满足光纤电流传感器0.2S级误差要求时延迟光纤偏振串音的允许波动范围。

To overcome the effect of polarization-maintaining fiber delay polarization crosstalk on the measuring accuracy of an all Fiber Optical Current Sensor (FOCS), the polarization error of the FOCS was studied by using the Jones matrix. The error model for the polarization-maintaining fiber delay polarization crosstalk was simplified, and the relation between the polarization crosstalk and the output was deduced based on the simplified model. The influences of the polarization crosstalk on FOCSs normalized scale ratio under a normal temperature and variable temperatures were analyzed respectively by simulation and analysis. The comparison between the experiment results and theory conclusions show that the simplified model is reasonable and the simulation result is correct. The actual temperature characteristic of the polarization-maintaining fiber delay polarization crosstalk was tested. Experimental results indicate that when there is polarization crosstalk in the fiber delay line, the ratio error of the FOCS is proportional to the current;when the current is constant, the higher the polarization crosstalk is, the higher the FOCSs ratio error is. Finally, the fluctuation range of the fiber delay line polarization crosstalk to meet the 0.2S class error of FOCS was put forward.