Study Of The Double Longitudinal Modes Reciprocal Bias Mechanism In Laser Gyro

As the core component of strapdown inertial navigation system,laser gyro has many advantages such as high accuracy,large dynamic range,high reliability,etc.,so that it has broad application prospects in aerospace and other fields.The lock-in effect of laser gyro is the main obstacle to its accuracy,the double longitudinal modes reciprocal bias effect is found in the experiment can well avoid the lock-in.This dissertation theoretically studies the mechanism of double longitudinal modes reciprocal,and obtains stable operating conditions of reciprocal bias,which provides theoretical guidance for the engineering application of double longitudinal modes reciprocal bias laser gyro,the specific research contents are as follows:1.The basic working principle of laser gyro was studied,and analyzed the main error sources of laser gyro,focusing on the lock-in effect of laser gyro,based on these,the mathematical model and Lamb coefficient calculation method of laser gyro in the double longitudinal modes are obtained by the third-order theory;2.Built a simulation platform in Simulink,simulated and analyzed the Lamb coefficient of the laser gyro in the double longitudinal modes,the necessary condition of double longitudinal modes reciprocal bias is given;simulated the light intensity tuning curve of the double longitudinal modes laser gyro and analyzed the characteristics of the double longitudinal modes tuning;based on the Runge-Kutta methods,the self-consistent equations of the laser gyro in the double longitudinal modes are solved,the working characteristics of the light intensity,input angular velocity and output angular velocity of the laser gyro in the double longitudinal modes are obtained,the impacts of the cavity length,tuning frequency and relative excitation of the laser gyro on the double longitudinal modes reciprocal bias phenomenon are analyzed respectively;3.The theoretical analysis results are preliminary verified by the double longitudinal modes reciprocal bias test of laser gyro.The light intensity tuning curve was obtained by the light intensity tuning characteristics test;in the experiment,tested the locking threshold within the range of light intensity tuning by experiment,by the experimental data,the impacts of frequency stabilization voltage on the laser gyro locking threshold and reciprocal bias is analyzed.In this dissertation,the double longitudinal modes reciprocal bias effect is used to eliminate the laser gyro lock-in,and the stable double longitudinal modes reciprocal bias phenomenon can be generated in the experiment,which has important reference value for the development of the zero locking threshold laser gyro.