Active spectroscopy of spontaneous Raman scattering of light by surface polaritons

A theoretical analysis is made of the spontaneous Raman scattering of a test wave by coherent surface polaritons, which are created by the difference frequency in biharmonic pumping. Formulas are obtained for the intensity of the scattering of the test wave. Numerical estimates show that this type of scattering produces much higher intensities than the scattering by noise surface polaritons.