Stimulated Brillouin scattering phase-conjugation fidelity fluctuations.

We observe shot-to-shot fluctuations in the far-field fidelity of stimulated Brillouin scattering phase-conjugate mirrors in the saturated reflectivity regime under various experimental conditions. The fluctuations, which are not seen in the reflectivity, reflect a partial breakdown in the discrimination mechanism that selectively amplifies the conjugate mode above the stimulated Brillouin scattering noise seed.