尾纤长度不对称导致的光纤陀螺振动误差分析

如何提高光纤陀螺在振动环境下的精度是光纤陀螺工程化过程中必须考虑的问题。当前，对于降低光纤陀螺振动误差的方法主要集中在改善光纤陀螺的机械结构和固定光纤环上。然而，Y波导与光纤环的尾纤长度不对称也是引起光纤陀螺振动误差的一个重要原因。首先根据弹光效应从理论上阐述了由振动所引起非互易相移的原理，进而分析证明了振动条件下左右两侧的波导尾纤与光纤环的尾纤长度之和不相等，即尾纤长度不对称是导致振动条件下非互易相移产生的一个重要原因。在此基础上推导出了振动条件下光纤陀螺两侧尾纤长度和之差与陀螺输出误差的理论关系式，并通过Matlab仿真了两侧尾纤长度和之差与陀螺输出漂移的关系曲线。

Analysis of vibration error in FOG due to fiber tail length asymmetry

Improving the precision of fiber optic gyroscope (FOG) in vibration environment is important in the application of FOG. Current research on reducing FOG vibration error are mainly concentrate on improving FOG mechanical structure and reinforcing fiber coil. However, fiber tail length asymmetry also has been demonstrated an important reason which can affect the vibration error of FOG. Firstly, the basic theory of phase shift of FOG caused by elastic-optic effect due to vibration was introduced. Then the length of fiber tail on the left and right asymmetry was shown to be the reason of nonreciprocal phase shift in the condition of vibration. Theoretical formula between the length difference of fiber tail in two directions and the output error of gyroscope was derived. Finally, simulations were performed to show the relationship between fiber tail length asymmetry and FOG output error.