Comparison of Observed and Predicted Stimulated Raman Scattering Conversion Efficiencies

We have measured the absolute Raman scattering cross section for the 1345‐cm−1 shifted Stokes line in nitrobenzene using a ruby laser. We have also measured the efficiency of conversion of radiation from a giant pulse ruby laser into stimulated Raman scattered radiation for this line. We have found that the average intensity needed to produce a given conversion is one or two orders of magnitude less than that predicted by the theory of Hellwarth using our measured cross section. We discuss some possible explanations for this disagreement.