Chemical Physics Letters, Vol.553, 26-29, 2012
Molecular vibrational dynamics in polyvinyl alcohol studied by femtosecond coherent Anti-Stokes Raman spectroscopy
We have performed femtosecond time-resolved coherent anti-stokes Raman spectroscopy (CARS) to study the vibrational dynamics in polyvinyl alcohol (PVA) film. We observed femtosecond coherent vibrational relaxation and CARS signal beats in PVA at room temperature. We found that the coherent vibrational relaxation of anti-symmetric CH2 stretching modes in PVA is faster than that of symmetric modes, probably due to faster vibrational energy transfer. The coherent vibrational relaxation of OH stretching modes was observed to be slower than that of CH2 modes, because OH stretching modes have less resonant energy transfer rate compared to CH2 modes. (C) 2012 Elsevier B.V. All rights reserved.