Laser Photoacoustic Spectroscopy of High Vibrational Overtones

Abstract

The nature of intramolecular energy transfer and mode coupling in highly vibrationally excited, polyatomic molecules can be studied by high overtone spectroscopy [1,2]. The details of the vibrational overtone spectrum corresponding to changes in vibrational quantum number of 5, 6, and 7 directly probe the vibrationally excited, final state. Since the absorption cross sections for these transitions are very small, typically less than one barn, photoacoustic spectroscopy can be used to detect these overtone absorptions.