Semiconductor Ring Laser Gyroscopes Modeling Design and Critical Performance Limiting Parameters

Abstract

In this thesis, SRLG has been mathematically modeled using rate equations of newlinecounter-traveling electric fields inside the gain medium and the resonant cavity. The Sagnac newlinebeat signal obtained by simulating the model is verified by rotating the experimental setup of newlinethe gyro. The sensitivity, which is found to be limited by locking of the counter-traveling newlinefields, is enhanced by proposing few novel designs and biasing techniques. Although these newlinetechniques improve the sensitivity of SRLG, the overall performance is still very poor newlinecompared to the military navigation standards. In order to identify the critical performance newlinelimiting parameters and phenomena, every metric of SRLG such as quantum limit, angle newlinerandom walk, scale factor stability, null shift and lock-in threshold have been thoroughly newlinemodeled in terms of material, geometry and environmental parameters. Moreover, effects of newlinenonlinearities such as spatial hole burning, mode coupling, gain saturation etc. on the SRLG newlinesensitivity have been evaluated. The critical performance affecting parameters are identified newlineand optimized to achieve best possible performance. For integrated SRLG, lock-in due to newlinenonlinear backscattering inside the semiconductor gain medium is found to limit the newlinesensitivity to 10 8 deg/h. Use of external coupled-cavity semiconductor ring lasers and newlinestimulated Brillouin scattering (SBS) based ring lasers as gyroscopes are proposed for high newlineperformance military applications.