Improving long-term temperature bias stability of an integrated optical gyroscope employing a Si3N4 resonator

The presence of polarization noise generated by the waveguide resonator limits the performance of a resonant integrated optical gyroscope(RIOG). Using silicon nitride(SiN) to fabricate a waveguide with an ultralowaspect-ratio can result in a resonator that only supports light transmission in a single-polarization state, suppressing polarization noise. We successfully fabricated a SiNresonator with a bending radius of 17.5 mm,a finesse(F) of 150, a quality factor(Q) of 1.54 × 10~7, and a propagation loss of 1.2 d B/m. The SiNresonator was used to construct a double closed-loop RIOG that showed long-term bias stability(3600 s) of 13.2°/h at room temperature, 14.8°/h at 40°C, 21.2°/h at 50°C, and 23.6°/h at 60°C. We believe this to be the best performance reported to date for a SiNresonator-based RIOG. This advancement paves the way for the wider application of RIOGs.