Free electron laser as a tool for pump-probe measurements of the vibrational relaxation in condensed phases

The infrared free‐electron laser (CLIO) was applied to the study of vibrational relaxation rates in condensed phases by one‐color pump‐probe experiment. In this paper we present the results of preliminary measurements involving small molecules (CO, CO2) in low‐temperature argon matrices and intermediate‐size molecules (acetonitrile, benzonitrile) in room‐temperature CCl4 solutions.