LOCALIZATION OF STIMULATED BRILLOUIN-SCATTERING IN RANDOM-PHASE PLATESPECKLES

This paper presents the first experimental evidence of the transverse localization of stimulated Brillouin scattering (SBS) emission to the laser beam axis, demonstrating that only a few small regions of plasma contribute to the emission. As a consequence, SBS reflectivity of the se regions is much higher than the average SBS reflectivity, by a fact or of similar to 50-100. These observations are consistent with the re cent concept of SBS growing mainly in ''active'' speckles, having an i ntensity higher than the average laser intensity.