HIGH-RESOLUTION SPECTRAL MEASUREMENTS OF THE STIMULATED RAMAN EMISSION FROM OPTICALLY-PUMPED D2O VAPOR

The spectra of the stimulated Raman emission from D2O vapor optically- pumped by a pulsed CO1 laser were measured with a heterodyne receiver having a high frequency resolution of 1.3 MHz. The measurements were c arried out for two D2O Raman cells of 4.3 m and 0.3 m length, and for various gas pressures. For gas pressures higher than 4 Torr, the measu red spectra had a width of a few tens of megahertz and peaked around t he Raman resonance frequency for both the two Raman cells, For gas pre ssures lower than 2 Torr, slightly different spectral characteristics were observed between the 4.3 m and 0.3 m cells. A brief discussion is given referring to the existing theory.