Probing of the vibrational quasicontinuum of molecules by the coherent active Raman spectroscopy method

An analysis is made of the use of coherent active Raman spectroscopy (CARS) in probing the vibrational quasicontinuum of molecules. An analytic expression is obtained for the nonlinear susceptibility χ⁽³⁾ in the case of a Lorentzian zone of "smearing" of harmonic states. A study is made of the profile of a CARS signal in the case of a Boltzmann distribution. Possible experiments are discussed.