谐振式光纤陀螺背向散射噪声抑制研究

摘要

Backscatter noise is one of the main noises in resonator fiber optic gyro(RFOG).Based on the principle for reducing the backscatter noise by carrier suppression method,the mathematical model was established for the influence of temperature and voltage on the gyro bias.It is theoretically proved that this method is largely affected by temperature and has higher circuit requirements.A new scheme of RFOG based on three-mode differential technology was put forward.In this scheme,the backscatter noise is decreased by operating three beams with large frequency intervals in the resonant cavity.A comparative experiment was conducted with traditional two-mode closed-loop gyro.The results show that the new scheme can effectively minimize the gyro noise,and both the maximum gyro bias and bias stability are improved by around 4 times.%背向散射噪声是谐振式光纤陀螺的主要噪声之一.基于载波抑制法降低背向散射噪声的原理,建立了温度和电压对陀螺零偏影响的数学模型,理论证明此方法受温度影响较大且对电路要求较高.提出了三频差动谐振式光纤陀螺新方案,该方案通过谐振腔内运行三束频率间隔较大的光波来抑制背向散射噪声.与传统二频闭环陀螺进行了对比试验,结果表明:新方案能有效地降低陀螺噪声,最大陀螺零偏和零偏稳定性改善约4倍.