Zwei-Photonen-Spektroskopie innerhalb der Dopplerbreite – ein neuer Weg zur Untersuchung von innermolekularen Energieumverteilungsprozessen

Abstract

A review on recent progress of high-resolution laser spectroscopy in the investigation of intramolecular vibrational redistribution (IVR) processes is given. Doppler-free two-photon spectroscopy is shown to offer the possibility to resolve rotational lines even within the dense electronic spectra of polyatomic molecules. In this way the influence of coupling to «dark» background states can be studied at different excess energies and the evolution of IVR from static coupling to a dynamic process is discussed. Both, the spectral perturbations observed at low excess energies as well as the homogeneous line broadening found for high excess energies point to Coriolis coupling as a responsible coupling mechanism in the IVR process of the prototype molecule benzene.