Abstract

Several methods of efficiently converting a laser beam with poor beam quality into one of good beam quality have been studied in the last few years. These include various techniques of phase conjugation and stimulated Raman scattering (SRS). In this paper we present a newly formulated theory of forward stimulated Raman scattering by a pump laser of spectral width much greater than the Raman linewidth. We use this theory to determine analytically when the spatial wave front of a seed Stokes beam may be preserved white it is amplified, particularly in the high-conversion (or strong depletion) limit, in which nearly all the pump photons are converted to Stokes photons.

© 1985 Optical Society of America