The infra-red fluorescence spectrum of multiphoton excited SF 6

Abstract

The infra-red fluorescence spectrum of SF 6 excited by CO 2 laser pulses and measured between 800 and 1500 cm -1, shows a very strong peak shifted to the red relative to the ν 3 absorption band. This reflects the vibrational energy distribution among the molecules and indicates that no quasi-continuum of oscillator strenghts in SF 6 in this region. A nonthermal energy distribution in the ensemble of molecules is found to exist at low excitation levels.