Observation of interference of direct and cascade processes in active spectroscopy of polaritons
Polivanov Yu.N., Sukhodol'skii A.T.
It is observed in experiment that the interference of threeand four-photon processes leads to deformation of the line shape and to the appearance of a doublet structure in the spectra obtained by active spectroscopy of Raman scattering of light by polaritons. The sign and the magnitude of the effective nonlinear susceptibility of third order χ^;^ 1.9X 10_i3 cgs esu are determined for the LiI03 crystal.