Excitation mechanism of the far-infrared sulfur dioxide molecular laser

Abstract

The published experimental data for the far‐infrared SO₂ molecular laser is correlated with the results of some new experiments. A satisfactory assignment of all of the lasing lines is presented. An excitation mechanism involving excitation to the first excited singlet electronic state, followed by crossing to the highly vibrationally excited levels of the ground electronic state, and then by selective vibrational relaxation, is shown to be consistent with the experimental data.