Chapter 9 - Stimulated Brillouin and Stimulated Rayleigh Scattering

Abstract

A light scattering process is said to be stimulated if the fluctuations are induced by the presence of the light field. Stimulated light scattering is typically very much more efficient than spontaneous light scattering. Stimulated Brillouin scattering (SBS) process leads to amplification of a Stokes wave propagating in any direction except for the propagation direction of the laser wave. However, SBS is usually observed only in the backwards direction, because the spatial overlap of the laser and Stokes beams is largest under these conditions. Electrostriction is also important both as a mechanism leading to a third-order nonlinear optical response and as a coupling mechanism that leads to stimulated Brillouin scattering. The scattering of light from isobaric density fluctuations that are driven by the process of electrostriction leads to electrostrictive stimulated Rayleigh scattering, whereas the scattering of light from isobaric density fluctuations that are driven by the process of optical absorption leads to thermal stimulated Rayleigh scattering.