Large signal characteristics of stimulated Brillouin scattering and Gaussian beam phase conjugation

Stimulated Brillouin scattering has an inherent threshold. The characteristics above this threshold must be analyzed in terms of a large signal backward traveling-wave parametric interaction. The conventional treatment is valid only below the threshold of stimulated scattering and is limited to small signals. Here, the large signal theory is applied to Gaussian beam phase conjugation. The results agree in all aspects with recent experimental measurements. It is found that, for phase conjugation mirror applications, the threshold can be eliminated by incorporating an auxiliary end mirror.<>