Ring Resonator Optical Gyroscopes-Parameter Optimization and Robustness Analysis

Semiconductor ring resonators as the core components of instruments and devices have found applications in the areas of telecommunications and sensors. In this study, the feasibility of using ring resonators as solid-state angular rate sensors (gyroscopes) based on the Sagnac effect is assessed, and an extensive analysis of the optimal values of resonator length, coupling, and detuning is carried out, for the drop port of a double-bus ring, and for an all-pass, single-bus ring, for different values of propagation losses, consistent with different available technologies. We show that for both the all-pass and the drop-port configurations, optimally undercoupled rings show larger extinction ratios and, thus, better resolutions than critically coupled rings of the same length, contrary to our initial intuitive assumption that critically coupled rings should offer the best resolutions. Our analysis also shows that the ring resonator gyroscopes require a technology-constrained optimization, with the propagation loss as the main factor that hinders the resolution, and that determines the optimum values of all other parameters, namely length, coupling, and resonance detuning. According to our model, standard-chip-sized racetrack gyroscopes are suitable for rate-and tactical-grade applications for selected, currently feasible low propagation loss waveguides.