Raman depolarization ratio of liquids probed by linear polarization coherent anti-Stokes Raman spectroscopy

International audienceWe present a simple analytical model to describe the linear polarization coherent anti-Stokes Raman scattering (CARS) spectroscopy. In this scheme, the pump and Stokes beams can have arbitrary linear polarization states and the CARS emitted signal is analyzed along two perpendicular directions. We concentrate on isotropic media without electronic resonances and show that only two polarization CARS measurements performed at the peak and the dip of a CARS spectrum are sufficient to deduce the Raman depolarization ratio, the resonant versus nonresonant contribution, the Raman resonance frequency and the linewidth.We demonstrate the applicability of our scheme to toluene and cyclohexane solutions