Equally-Spaced Multi-Frequency Laser Emission Generated by Two-Color Stimulated Raman Effect. –Enhancement of Rotational Lines and Suppression of Vibrational Lines–

Abstract
A two-color laser beam separated by 587 cm-1 is focused into pressurized hydrogen to generate stimulated Raman emission. By optimizing the hydrogen pressure and the beam focusing condition, only rotational lines are generated in the near-UV region; the vibrational lines are completely suppressed. The rotational lines are further enhanced by using a circularly polarized beam.