在全光纤开环光纤陀螺中 ,利用压电陶瓷调制器可以为光纤陀螺提供互易性正弦相位偏置 ,但相位调制中的寄生非线性会对陀螺测量产生影响。从理论上给出了二倍频非线性相位调制情况下开环光纤陀螺输出信号的一、二、四次谐波表达式 ,分析了相位调制非线性对陀螺工作点测量与信号解调的影响 ,实验验证了相关结果。实验结果与理论分析表明在陀螺应用中必须采取措施抑制非线性相位调制的幅度。 In all-fiber open-loop FOGs, a reciprocal sinusoidal phase offset can be provided for the FOG by using a piezo-ceramic modulator, but parasitic non-linearity in phase modulation can have an effect on the gyro measurement. The harmonic expressions of the first, second and fourth harmonics of the output signal of the open-loop FOG are given theoretically, and the effect of phase modulation nonlinearity on the measurement and signal demodulation of the gyroscope is analyzed. , The experiment verifies the related result. Experimental results and theoretical analysis show that in gyro applications, measures must be taken to suppress the amplitude of nonlinear phase modulation.