激光器偏振特性对谐振式光纤陀螺性能的影响

Influence of Laser Polarization Characteristic on Performance of Resonator Fiber Optic Gyro

摘要:

激光器是谐振式光纤陀螺(RFOG)的重要组成部分,其光学噪声严重地限制了RFOG的输出精度。通过建立激光器偏振特性的数学模型,分析了激光器的偏振消光比、对轴误差和偏振本征态相位差对RFOG性能的影响,并通过实验验证了模型的正确性。此外,提出一种基于强度调制基频解调信号的方案,以补偿RFOG中非理想偏振态的振幅波动。实验表明,利用该方案可将非理想偏振态下振幅波动引起的陀螺输出波动减小12dB以上。

Abstract:

Laser is an important part of the resonator fiber optic gyroscope (RFOG) and its optical noise severely limits the output accuracy of RFOG. In this paper, the mathematical model of the laser polarization characteristic in RFOG was established. Then, the effects of polarization extinction ratio, alignment error and phase difference between two polarization eigenstates on the performance of RFOG were analyzed, and the model was verified by experiments. In addition, a scheme based on the first harmonic demodulated signal of the intensity modulation was proposed to suppress the amplitude fluctuation of the undesired polarization state in the RFOG. Test results indicate that the drift of gyro introduced by the amplitude fluctuation of the undesired polarization state is reduced by more than 12dB.