Molecular vibrational dynamics in polyvinyl alcohol studied by femtosecond coherent anti-stokes Raman spectroscopy

► Fs CARS technique enables us to detect the coherent vibrational relaxation in PVA. ► We observed the coherent vibrational relaxation time of CH2 and OH stretching modes including the contribution of inhomogeneous broadening. ► Energy flow of higher frequency mode for CH2 is faster than the low frequency mode. ► The coherent vibrational relaxation of OH modes was observed to be slower than CH2.