The Theoretical Research And Simulation Of The Magnetic Effect In Little Non-planar Resonators

To reduce the magnetic effect is important for the research of high precision and super high precision ring laser gyroscopes. There has been some research on the magnetic effect of ring resonators, and a few methods for reducing the magnetic effect have been proposed. However, there still exist some problems in those articles. In this thesis, a mathematic model for calculating the magnetic sensitivity is presented. The magnetic effect in little non-planar ring resonators is analyzed in detail, and the theoretical analysis is partly proved by the experiment. The thesis is summarized as follows:1. A mathematic model for calculating the magnetic sensitivity in square planar ring resonators is presented. The model takes into account the following parameters such as the image rotation angle, the magnetic field, the phase shift of the mirror and the difference of the reflectivity amplitudes for's'and'p'type polarizations of light simultaneously. The relationship between the magnetic sensitivity and those parameters is analyzed, and several important parameters has been found out. Moreover, a method to reduce magnetic bias has been proposed by reducing the phase shift or the sum of the phase shift of the mirror to 0. Those results and methods are based on theoretical analysis, and their validity need to be proved by experiment in the future.2. A mathematic model for calculating the ellipticity of the output beams in square planar ring resonators is established. The model takes into account the following parameters such as the phase shift of mirror, the angle between the S-polarization and the substrate'fast'axis and the birefringence angle. By analyzing the mathematic model of the ellipticity, the stress effect of the output mirror has the unsymmetrical influence on the ellipticities of clockwise and counterclockwise output beams. Based on the theoretical analysis, because of the the stress effect of the output mirror, the alignment method to decrease the magnetic bias by controlling the distortion angle of square ring resonators, which is proposed in the patent that is presented by R. H. Moore has been found ineffective.3. Considering the disadvantage of the former frequency stabilization method, a new frequency stabilization method for the S polarized output beam is presented. The frequency stabilization is completed within 10 seconds. The efficiency of the frequency stabilization has been improved greatly. The intensity fluctuation of frequency stabilized output beam is less than 2.35%.4. The clockwise and counterclockwise output beam ellipticity measuring system has been established. The ellipticity of clockwise and counterclockwise output beam has been measured. The unsymmetrical influence the ellipticities of clockwise and counterclockwise output beams which is caused by the stress effect of the output mirror is verified by this experiment. Based on the experimental results, because of the the stress effect of the output mirror, the alignment method to decrease the magnetic bias by controlling the distortion angle of square ring resonators, which is presented by R. H. Moore has been found ineffective.