谐振式集成光学陀螺解调特性分析

Demodulation characteristics of resonator integrated optical gyro

基于激光器频率谱检测技术,沿着光的传输方向分析了光波在谐振式集成光学陀螺系统中的传播,结合输入信号特征,建立频域内的数学模型,通过数值仿真和实验得到了调频检测系统下的解调曲线。按照光的传输方向:激光器、声光晶体移频器、光波导环形谐振器、探测器,利用贝塞尔函数展开和光场耦合模理论分析了谐振式集成光学陀螺解调特性,及其调频调制检测系统解调输出信号与谐振频率偏差之间的关系。通过数值计算,分析了解调曲线的变化规律,得到了施加在激光器压电陶瓷驱动器上调制波形的最佳调制系数。在实验上搭建了激光器频率调制解调技术系统,得到了解调曲线。数值仿真和实验结果表明,当调制系数M=2时,线性工作区间斜率最大,解调曲线最好。实测形状与理论分析结果相符,从解调信号得到±2×103rad/s的陀螺动态范围。

According to the light transmission directions , we analyzed the light propagation in the resonator in-tegrated optical gyro system based on laser frequency modulation spectrum technique .Combining with the fea-ture of the input signal , we established the mathematical model in frequency domain .The demodulation curve was obtained in frequency modulation method by numerical simulation and experiment .Firstly, according to the transmission direction of light：the laser , acousto-optic crystal frequency shifter , optical waveguide ring re-sonator, detector, we analyzed the demodulation characteristics of resonator integrated optical gyro using Bes -sel function and optical field coupled mode theory as well as the relationship between the frequency modulation demodulation output signal and the resonant frequency deviation .Then, we analyzed variation rule of demodu-lation curve and obtained the best modulation coefficient applied in laser′s piezoelectric ceramic transducer drive.Finally, we built a laser frequency modulation and demodulation technology system in experiment and obtained the demodulation curve .When the modulation coefficient M=2 , the linear interval slope is maxi-mum, and the demodulation curve is the best .Numerical simulation and experimental results show that the measured shape is consistent with the theoretical prediction .From the demodulation signal , a gyro dynamic range of ±2.0×10^3 rad/s is obtained .