CORRELATION-EFFECTS IN PUMP-DEPLETED BROAD-BAND STIMULATED RAMAN AMPLIFICATION

We report gain depletion measurements in broadband stimulated Raman amplification of collinear and crossed beams in hydrogen as a function of correlation between pump and Stokes. Pump depletion varies from 40% for uncorrelated beams to 80% for correlated beams. The width of the correlation peak in the gain is larger in the depleted regime than in the non-depleted regime, but in both cases it is of the order of the inverse laser bandwidth. Pump depletion is lower for crossed beams due to the decrease in the interaction length, but no effect on the correlation peak shape is observed.