Coupled Spiral Interferometer Gyroscope

This paper reports a study of the sensitivity to an absolute rotation of an optical gyroscope in which the sensing element is a coupled spiral interferometer (CSPIN), which is a spiral waveguide with coupling between adjacent arms. The two physical sensing mechanisms that contribute to this sensitivity are discussed. Numerical simulations show that after optimization, a CSPIN gyroscope has the same maximum possible sensitivity as an optimized resonant waveguide optical gyroscope with the same radius and loss coefficient. This maximum sensitivity is independent of the number of arms, and it decreases as the reciprocal of the waveguide loss coefficient.