Reduction of Raman Scattering in a Plasma to Convective Levels Using Induced Spatial Incoherence

Abstract

We present measurements of the Raman backscatter produced by laser-plasma interaction where the laser focal profile was smoothed by induced spatial incoherence (ISI). The Raman backscatter with the ISI beam is much smaller than that with an ordinary beam. The onset of Raman backscattering with ISI followed the predictions of a convective gain model to within 30% in intensity.