干涉式光纤陀螺中Shupe效应与Sagnac效应的分离

摘要

热引入的零偏漂移即Shupe 效应是提高光纤陀螺精度面临的最大难题。基于Shupe效应与光纤陀螺的Sagnac效应具有本质的不同特性，即Sagnac效应引起的相移只与几何尺寸有关，而与光传播的介质特性无关，提出了一种新型的不受温度梯度影响的光纤陀螺。利用两个偏振模式在光纤陀螺环中交替或同时传播可以将Sagnac相移与Shupe误差相移分离开来，基于两种偏振模式分时传播实验，初步验证了该理论的可行性。并且提出了一种新型的偏振交替干涉式光纤陀螺模型以改进其性能。%Thermally-induced bias drift,i.e. Shupe effect is one of the challenges that improve the accuracy of inter-ferometric fiber-optic gyroscope (IFOG). A thermally-bias-free scheme for an IFOG is presented,which is based on the different characteristic between the Sagnac effect and the Shupe effect that the Sagnac phase is related only to geo-metric layout of the sensing loop and is independent of the medium’s characteristic of light propagation. This paper exploits light propagations along two eigen-axes of the polarization maintaining fiber of IFOG to separate the rotation phase from the error phase. An experiment is designed based on two polarization mode propagates alternately in the sensing loop,and the feasibility of the theory is preliminarily verified. Meanwhile a detection scheme is also proposed that polarization mode changes alternately to improve the thermal performance of fiber optic gyroscope.