THERMAL LENSING STUDY ON THE VIBRATIONAL-RELAXATION OF HIGHLY EXCITEDCHLOROFLUOROETHANE

Vibrational relaxation rate of CClF2CHCl2 gas excited by TEA CO2 laser in the presence of various addition gases was measured by the thermal lensing (TL) technique. The vibrational relaxation rate was higher fo r large molecules, implying that off-resonant vibrational energy trans fer is playing a role in the relaxation process. Furthermore, the rela xation was fast for high fluence irradiation. By comparing the present results with the product yield measurement of infrared multiphoton di ssociation (IRMPD), it seems that the collision partner effect of the vibrational relaxation rate measured by the TL technique is correlated to the addition-gas effect in the IRMPD rate. (C) 1998 Elsevier Scien ce B.V.