Theory of Stimulated Raman Scattering

Relations which describe the gain that is produced by the stimulated Raman scattering of intense light in a Raman-active material are developed entirely in terms of measurable material parameters (such as the ordinary Raman scattering cross sections). It is this gain which must overcome propagation losses in order to achieve the laser action that has been observed from this effect. Expressions for the gain are derived for scattering material either in thermal equilibrium or in certain nonequilibrium conditions. The dynamical equations governing the time behavior of the Raman-laser light are discussed.