基于布里渊散射的保偏光纤环应力分布特性研究

Characteristic study on strain distribution in polarization maintaining fiber coil based on Brillouin scattering

保偏光纤环是光纤陀螺的核心部件,其性能受温度的影响较大,主要表现为热致互易相移,影响光纤陀螺的精度。针对该问题,提出采用应力分布法测量光纤环的温度非互易相移。通过对不同温度点的光纤环应力分布数据进行分析,建立光程对中数学模型,基于该模型对光纤环的尾纤进行适当调整,改进其光学对称性,降低由温度变化引起的非互易相移。通过陀螺整机实验表明:该方法能大幅提高光纤陀螺的精度,过程简单方便,对成品光纤环具有一定的修复作用,提高了成品率,实用性较好。

As a key component of the polarization-maintaining fiber optic gyroscope,the fiber coil is sensitive to the temperature which mainly shows that producing thermally induced nonreciprocity phase shift.To overcome this problem,a novel thermally induced nonreciprocity phase shift measurement method based on strain distribution was proposed in this paper.The strain distribution data of fiber coil at different temperatures was analyzed,and the model of optical path centering was established.Modifying the pigtail of fiber coil with the model,and the optical symmetry properties can be adjusted consequently.In order to verify the effect of our work,the modified pigtail was equipped to the gyroscope to test its performance,and the result shows the accuracy of the gyroscope becomes much better than before.The method proposed in this paper is helpful to increase the yield rate of fiber coil,and it also has the advantage of easy to carry out.