A time-resolved study of rotational and vibrational excitation and relaxation in the13CH3F optically pumped far-infrared laser

The rotational and vibrational energy transfer processes of the¹³CH3F optically pumped far-infrared (OPFIR) laser have been studied in a time-resolved experiment. The experiment uses a tunable millimeter and submillimeter spectroscopic technique as a diagnostic probe. Included are observations of the fast processes that closely connect other states within to the directly pumped level, a vibrational swapping mechanism that transfers excitation from to other states, vibrational relaxation due to both wall collisions and molecule-molecule collisions, the nonunity probability of vibrational deactivation in a wall collision, and pump saturation and hole burning effects due to the CO2pump laser. All of these observations are accounted for in the context of a numerical simulation. This results in a complete map of all of the collision-induced rotation-vibration transitions of importance to this basic OPFIR system including quantitative cross sections for the relevant processes.