Table of Contents
Laser Chemistry
Volume 7 (1987), Issue 5-6, Pages 305-331

Multiphoton Absorption of 12CF3I, 13CF3I, CF3Br and SF6 by a High Pressure CO2 Laser

C.E.A.-I.R.D.I., Département de Physico-Chimie, Centre d'Études Nucléaires de Saclay, Gif-sur-Yvette Cedex 91191, France

Received 1 August 1986; Accepted 18 December 1986

Copyright © 1987 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An investigation of the IR multiphoton absorption (MPA) of 12CF3I, 13CF3I, CF3Br and SF6, excited in cell by a 10 Bars TE CO2 laser is reported. The spatial, spectral and temporal characteristics of the laser emission versus the grating position have been carefully investigated. The main result is that the peaks observed in the different MPA spectra are undoubtedly correlated to the gain curve of the laser and not to the fine molecular spectroscopy.

This result is discussed in comparison with published similar works. The most likely explanation involves a laser bandwidth effect associated with a background of weak but rather dense resonances (typical spacing of 0.1–0.2cm−1). The MPA cross section of 13CF3I is about half that of 12CF3I pointing out the probable rôle of Fermi resonances.