谐振式光纤陀螺是一种基于Sagnac效应的高精度惯性传感器。作为一种互异性噪声,光纤谐振腔输入功率的波动会造成陀螺的检测误差。首先,分析了光纤谐振腔输入功率波动产生噪声的机理。通过对不同输入功率下的谐振腔传输特性和陀螺解调输出的理论及实验分析得到了谐振腔输入功率波动引起的检测误差的表达式。当输入角速度为500(°)/s、输入功率为0.69 mW时,0.007 5 mW的功率波动会引起5.26(°)/s的检测误差。其次,研究了谐振腔输入功率波动对陀螺标度因数的影响。通过计算发现随着输入功率波动的增大,解调曲线的线性区将会发生扭曲,同时陀螺的标度因数非线性度会恶化,为谐振式光纤陀螺中输入功率波动噪声的估测提供了参考。
Resonator fiber optic gyro (RFOG) is a high accuracy inertial rotation sensor based on Sagnac effect. As one of reciprocity noises in RFOG, input intensity fluctuation of fiber ring resonator(FRR) would lead to detection error. Firstly, the mechanism of noise induced by FRR input intensity fluctuation was investigated. Transmission characters of FRR and demodulation output with different input intensities were researched theoretically and experimentally. The expression of detection error caused by input intensity fluctuation was derived. When rotation rate was 500 (°)/s and input intensity was 0.69 mW, a variation of 0.0075mW would cause an error as large as 5.26 (°)Is. Secondly, the effect of input intensity fluctuation on scale factor was studied. It was found that the linear region of demodulation curve would be distorted as input intensity fluctuation increase and scale factor nonlinearity of gyro output would deteriorate too. This work proved a reference for estimating input intensity fluctuation noise in a RFOG system.