Brillouin scattering measurements from plasmas irradiated with spatially and temporally incoherent laser light

Stimulated Brillouin scattering spectra have been measured from plasmas produced by spatially and temporally incoherent laser light. The measured backscatter spectra and intensities differ substantially from measurements of Brillouin scattering with coherent illumination. Backscatter is strongly suppressed and the Brillouin signature in the spectra disappears. This quenching of stimulated Brillouin scattering is observed even when the laser coherence time is much larger (10\ifmmode\times\else\texttimes\fi{}) than the predicted convective saturation time of the stimulated Brillouin scattering instability.