Intracavity double resonance in the CH_3OH submillimeter laser

Abstract
An intracavity double-resonance technique has been used to study three K-type doublets in the portion of the CH3OH torsional–rotational–vibrational level structure which can be pumped by the CO2 10R(38) laser line to produce submillimeter (SMM) laser action. Measurements of the doublet spacings yield a value of S(4) = 2.1(1) × 10−9 for the first excited state of the ν8 vibrational mode. Measurements of the pressure and rf power dependence of the amplitude and halfwidth of the double-resonance signals produce a new evaluation of the rotational relaxation rate and other useful information pertinent to SMM laser dynamics.