Abstract

It has been predicted and observed that the gain in broadband stimulated Raman amplification depends on the pump-Stokes correlation.¹ It was previously demonstrated that maximum Raman gain, equal to the single mode gain, was obtained when the pump and input Stokes were correlated. The width of the correlation peak was proportional to the inverse laser bandwidth. In most applications involving stimulated Raman scattering it is desirable to operate in the pump depletion regime for efficient conversion to the Stokes. It is therefore important to determine the degree to which the pump and input Stokes must be correlated under pump depletion conditions to obtain high pump conversion. We observe a maximum 70% pump depletion at a relative relay of zero between the pump and input Stokes. Conversion drops to 40% when pump and input Stokes are decorrelated. The width of the correlation peak is comparable to the inverse of the pump bandwidth. We will present data comparing results obtained for different laser bandwidths, for noncollinear geometries and for negligible pump depletion. We shall also present the results of numerical calculations that model our experiments.

© 1990 Optical Society of America