消偏型光纤陀螺的原理及应用分析

干涉型光纤陀螺是通过光纤环的Sagnac效应来敏感外部的旋转角速度,在实际的光纤陀螺系统中,Sagnac效应十分微弱,光波偏振态的随机变化引起陀螺的输出漂移和标度因数的不稳定性,从而影响陀螺的性能,采用光学消偏方法可以减小偏振态对光纤陀螺性能的影响.运用琼斯矩阵分析Lyot光纤消偏器的原理及输入输出端口的互易性,探讨Lyot消偏器的结构参数,结合系统中光信号的特点分析了消偏器对光纤陀螺的影响,并探讨了消偏型光纤陀螺的最优结构.消偏光纤陀螺的测试采样输出数据维持在36.5～37.9,整体来看输出平稳,噪声得到了明显的抑制,从而验证了消偏光纤陀螺的原理及其结构设计的可行性.

Principle and practical analysis of depolarized fiber optic gyroscope

The interference fiber optic gyroscope (FOG) is a device that measures outer angle velocity by using fiber coil's Sagnac effect. However, fiber coil's Sagnac effect is minimal, and the random changing of light-wave's polarization state greatly affects FOG's output drift and scale factor's instability, impairing FOG's performance. The method of using optic depolarizer can reduce the effect of the state of polarization on the performance of FOG. An analysis was done on the principle of the Lyot depolarizer and the interchange character of input and output ports by using Jones matrix, and a probe was done the structure parameter of the Lyot depolarizer. Combining with light-wave's character in FOG, further analysis was done on the effect of the Lyot depolarizer on FOG and the best structure of FOG with depolarizer. Experiments show that FOG's output data maintains between 36.5 and 37.9, the data is stable in whole, and noises are restricted effectively, which proves the theory of depolarized FOG and the feasibility of FOG's structure design.