Rotational influence on multiphoton absorption efficiency in SF6-N2 mixtures

Abstract

The results of pulsed IR photoacoustic spectroscopy measurements of multiphoton absorption and rotational relaxation processes in SF 6 -N 2 mixtures are presented. Total average number (〈n〉 total ) of absorbed photons per one absorbing molecule (SF 6 ) during the laser pulse was compared with average number of absorbed photons (〈n〉 v ) really stored in SF 6 vibrational modes, using generalized coupled two-level model. Obtained results can be used to confirm or predict the excitation level (〈n〉 v ) of absorbing molecule during the laser pulse, as a function of added buffer-gases. This approach could allow one to control laser field - molecule interaction in different gas mixtures, understand the efficiency of collisional effects (especially rotational relaxation) and their positive and negative influence on absorption characteristics of irradiated polyatomic molecule. © EDP Sciences.