Abstract
An analytical theory of the operation of all-fiber Brillouin ring lasers that accounts for pump depletion is presented. Expressions for stimulated Brillouin scattering lasing threshold power, output Stokes power, and conversion efficiency are derived. It is shown that the fiber cavity detunes from its resonant value owing to the buildup of the counterpropagating Stokes wave, which can be a limitation in the performance of all-fiber resonator systems. The application of the theory is in the design and optimization of performance parameters of devices using all-fiber ring resonators, particularly Brillouin lasers and gyroscopes.