ON THE MECHANISM OF VIBRATIONAL DEPHASING IN LIQUID BENZENE BY COHERENT ANTI-STOKES-RAMAN SCATTERING USING INCOHERENT-LIGHT

Coherent anti-Stokes Raman scattering using incoherent light (I-(2)CAR S) for the ring breathing mode of neat benzene is analyzed using a Bro wnian oscillator lineshaping model. Three low frequency modes of benze ne are investigated for their possible role in the vibrational dephasi ng process. Unlike cw CARS, it is found that I-(2)CARS can strongly di scriminate between the dephasing activity of the three low frequency m odes and suggests that rotation about the C-6 axis is responsible for dephasing in this case. This agrees with previous findings in femtosec ond CARS experiments on the liquid. (C) 1998 Elsevier Science B.V. All rights reserved.