STIMULATED SCATTERING WITH DISTRIBUTED-FE EDBACK IN A SCATTERING MEDIUM

The effect of a distributed feedback on stimulated Brillouin scatterin g (SBS) is considered. The feedback is due to linear scattering by ran dom inhomogeneities or microinclusions in the medium. A theoretical an alysis is made taking account of focusing, in this medium, of laser pu mp radiation with different degrees of spatial coherence. It is shown that, in spite of the beam attenuation on increase in the scatterer co ncentration, the SBS threshold may decrease because of the distributed feedback. The range of conditions under which this effect can appear is determined. A well-defined maximum of the SBS efficiency, considere d as a function of the scatterer concentration, can be used to obtain information on the scattering inhomogeneities.