谐振型光纤陀螺(RFOG)因具有敏感光纤短和体积小等优点而备受关注。分析了激光线宽、光纤环形谐振腔(FRR)及检测技术对RFOG灵敏度的影响。依据RFOG信号检测方法, 推导了受光电检测器灵敏度限制的RFOG灵敏度公式, 并给出了考虑激光线宽和腔内偏振轴90°旋转的RFOG灵敏度修正公式。基于多光束干涉原理,分析了数字调相电压的误差和噪声对灵敏度的影响。仿真结果表明, 为获得高灵敏度, 针对不同的激光线宽应选取不同的FRR腔长, 偏振轴90°旋转熔接的两边长度差应为保偏光纤半拍长的奇数倍, 数字调相电压的噪声方均根值应小于0.22 V。该工作为高精度RFOG的设计提供了理论指导。

Resonant fiber optic gyro (RFOG) has attracted many attentions due to its advantages such as short-sensitive fiber and small size. The influences of laser linewidth, fiber ring resonator (FRR) and detection technology on the sensitivity of RFOG are analyzed. According to the detection method for RFOG signal, a formula of RFOG sensitivity limited by photoelectric detector sensitivity and a correction formula of RFOG sensitivity considering laser linewidth and 90° polarization-axis rotated splice are derived. The sensitivity influenced by error and noise of digital phase modulation voltage is studied based on multi-beam interference principle. The simulation results show that, in order to get high sensitivity, the length of FRR should be selected according to laser linewidth, and the length of two sections of fibers in both sides of 90° polarization-axis rotated splice should be set as odd times of the half-beat length of polarization maintaining fiber. Additionally, the root-mean-square of digital phase modulation voltage noise should be less than 0.22 V. The work provides theoretical guidance for the design of high precision RFOG.