Eliminating Mirror Misalignment in Ring Laser Gyros in Real-time
G-F. Lu, S-L. Jin, H. Luo and Z-F. Fan
In this paper the misalignment interrelationship of two adjacent spherical mirrors in a square ring laser gyro is investigated in details. The results show that optical beam path perturbations induced by the misalignment of one spherical mirror can be partly balanced by adjusting the misalignment of the other spherical mirror. Then the experimental data also show that the ray decentration-induced intensity attenuation of the laser is much severer than the ray tilting-induced. According to these characteristics, a real-time control system based on an improved angle controller is designed to eliminate mirror misalignment in terms of practical operation of ring laser gyros. In temperature experiments (-40 to 60ºC), the optical intensity attenuation decreases from 37 to 14% with this system.
Keywords: Ring laser gyro, ring resonator, mirror misalignment, angle controller, phase sensitive synchronized demodulator, real-time control system