Investigation of tunable stimulated Raman scattering by light mixing in liquid N2

Abstract

High‐order tunable anti‐Stokes Raman scattering is produced by mixing the radiation of a Q‐switched ruby laser and that of a dye laser in liquid nitrogen. All investigated orders of both ruby laser and dye laser anti‐Stokes radiation are found to have the same ruby laser power threshold of about 0.5 MW. The intensities of the anti‐Stokes radiation are found to increase linearly with ruby laser power once threshold has been surpassed appreciably. The dye laser anti‐Stokes radiation does not exhibit a dye laser threshold power. The results can be explained by a simple theoretical model which treats the ruby laser as a pump for coherent molecular oscillations.