Abstract

Broadband pump and/or seed beams input to a Raman amplifier, if not exactly collinear, will yield a broadband Stokes output spectrum which is fanned or angularly dispersed. The direction of maximum gain for growth of any component of the Stokes spectrum is found from a four-wave mixing phase matching condition. The relative angle a between the high gain directions for distinct Stokes lines will be much smaller than the angle θ between pump and Stokes directions, with a ratio of where γ is the spectral separation and ω_s is the Stokes frequency.

© 1989 Optical Society of America