Analysis of a fiber-optic passive loop-resonator gyroscope: Dependence on resonator parameters and light-source coherence

Analysis has been made of a fiber-optic passive loop resonator, the heart of the gyroscope. The performance characteristics are heavily dependent on the resonator parameters, such as coupling intensity loss of the input light, coupling coefficient between two fiber lines in an evanescent-field directional coupler, and losses of the light traveling in the fiber loop, as well as on the temporal coherence of the input light. A two input and two output system is considered for a passive loop-resonator gyroscope. Differential output operation of the two output signals is described.