Stabilization of a phase of conjugated wave at SBS with feedback on standing phase gratings

The theoretical analysis has been made and the calculations have been performed to define the mechanism of phase conjugation for the case of pump beam self-crossing in the medium active to stimulated Brillouin scattering (SBS) with its reflection back from the focusing mirror. It has been shown that in these circumstances phase conjugation can be realized through nondegenerate Brillouin four-wave mixing with feedback on standing phase gratings. The threshold value of the gain increment of the conjugated wave has been defined.