Order statistics of high-intensity speckles in stimulated Brillouin scattering and plasma-induced laser beam smoothing

We have studied plasma-induced smoothing due to stimulated Brillouin scattering (SBS) under the aspect of the extremal statistics of smoothed laser beams. As pointed out in the work by Rose and DuBois (1994 Phys. Rev. Lett. 72 2883), scattered light can be subject to uncontrolled (or even 'explosive') behaviour, associated with a critical gain value for SBS. In this work we show how this critical behaviour can be predicted on the basis of the order statistics of laser speckle fields, and we analyse the transition to uncontrolled behaviour of the laser beam due to the dominance of high intensity speckles. (paper)