Sensitivity limits of coupled resonator optical waveguide (CROW) gyroscopes when subject to material losses

In recent years there has been a growing interest in optical microresonators as viable low cost on chip micro-optical gyroscopes with navigation grade sensitivities. Here, we analyze and compare the rotational sensitivity of coupled resonator optical waveguide (CROW) gyroscopes to equivalent single resonator gyroscopes under various geometric constraints and device parameters. We show that the CROW gyros offer a sensitivity enhancement over conventional single resonator gyros at low propagation losses. However, the single ring resonator gyro is found to be more stable over a wider range of propagation losses as well as boasting greater sensitivities for larger propagation losses compared to a CROW of the same size. Furthermore, an analysis of the maximum achievable sensitivity for different material technologies (Hydex, silicon oxynitride, and SOI) is conducted. While all materials achieved tactical grade sensitivities, Hydex shows the greatest potential for CROW gyros because of the stability of its sensitivity over a wide range of device parameters.