Rotation sensing with optical ring resonators

Gyroscopes based on optical ring resonators have the potential to offer high-performance rotation sensing in a device that is more compact than the commercially successful fiber-optic gyroscope (FOG). In the research presented in this dissertation, we studied two recent developments in optics, namely slow-light coupled-resonator waveguides and air-core photonic-bandgap fibers (PBFs), to see whether either can be used to improve upon existing resonant optical gyroscopes.;First, we examined a number of recently proposed slow-light coupled-resonator gyroscope configurations. Using physical and mathematical arguments, we demonstrated that no coupled-resonator gyroscope offers any fundamental sensitivity enhancement over a conventional resonant fiber-optic gyroscope (RFOG) of the same size and loss. We also identified several factors that severely limit the practicality of coupled-resonator gyroscopes. Our study shows that coupled-resonator gyroscopes do not provide a viable path toward improvement in the state of the art in rotation sensing with optical ring resonators -- they offer no fundamental advantage over the RFOG, while suffering from a number of daunting practical disadvantages.;Second, we experimentally characterized and theoretically modeled an RFOG with a sensing coil made from air-core PBF. Air-core PBFs have great potential for application in the RFOG because they reduce both the Kerr-induced drift and the thermal polarization instability, two error sources that limited the performance of previously studied RFOGs made with conventional solid-core fiber. However, directional couplers for air-core PBF do not yet exist, so the resonant loop in an air-core RFOG must be closed in some other way. The fiber ring resonator in our experimental RFOG consisted of an air-core PBF coil connected to a directional coupler made from solid-core fiber. With this configuration, we measured a random walk of 0.055 °/s1/2 and a long-term drift with a standard deviation of 0.5 °/s and a peak-to-peak variation of 2.5 °/s over 1 hour. These figures set the first quantitative landmarks in rotation sensing using an air-core fiber in an RFOG. We also modeled the sources of error in our air-core RFOG and identified key areas for future improvement. We project that with straightforward improvements, tactical-grade performance should be possible in a next-generation air-core RFOG.