Mathematical models of light waves in Brillouin-scattering fiber-optic gyroscope resonator

The Brillouin-scattering fiber-optic gyroscope (BFOG) is a new-generation miniaturized high-precision fiber-optic gyroscope. By focusing on the light characteristics of the BFOG resonator, we derive a recursive relationship for the intensity of light of different orders by using the coupled equations for stimulated Brillouin scattering. We then establish mathematical models of the light characteristics, threshold power analysis, and optimum resonance condition analysis. Based on these models, we derive a functional relationship between the incident pump light intensity, light intensity in the cavity, the intensity of each Stokes wave order, and emitted light intensity. Finally, we simulate and quantify the threshold power and resonance critical condition influenced by several main factors including the insertion loss, coupling coefficient, and transmission loss.