Stimulated Brillouin scattering of a laser beam in a plasma channel

A high-power laser propagating through a plasma creates a low density channel through which it propagates self guided. This equilibrium, however, is unstable to Brillouin backscattering above a threshold power. A nonlocal theory of stimulated Brillouin scattering (SBS) reveals that the growth rate is significantly reduced due to a geometrical factor; nonetheless, it remains an important process in laser-produced plasmas. It is also a limiting process in a plasma loaded free electron laser (FEL).