为了提高陀螺的精度,提出了一种新型双光程光纤陀螺.在光纤环两端各连接一个偏振分束器,使得偏振光依次沿保偏光纤的快轴、慢轴传输两圈,其有效光程加倍,进而实现陀螺的Sagnac效应加倍.针对该光纤陀螺在温度场扰动下的非互易问题,分析了其特殊结构带来的温度致非互易误差,利用有限元分析法建立了相应的Shupe误差模型,并对光纤环90°熔点位置、光纤环折射率温度系数改变对Shupe误差影响进行了相应的理论计算与仿真分析,结果表明90°熔点置于光纤环中点或者选用折射率温度系数满足特定条件的光纤环可减小其Shupe误差.

In order to improve the precision of fiber-optic gyroscope, a novel fiber optic-gyroscope with double optical length was presented. By employing two polarization beam splitters, polarized light propagated twice along the slow and fast axes of the polarization maintaining fiber sensing coil in sequence to double its effective optical length and precision further. The thermal induced non-reciprocity in the proposed fiber-optic gyroscope was analyzed according to its special structure. With finite element analysis technique, modeling and simulation of the Shupe bias errors were also conducted. By modifying the 90°splicing point to the middle of the sensing coil or choosing appropriate fiber with special refractive index temperature coefficients , the Shupe bias error can be reduced significantly, which is low enough to meet the requirement of fiber optic-gyroscopes with high performance.