Stimulated Kerr scattering and reorientation work of molecules in liquidCS2

A Stokes shifted superbroadening stimulated scattering has been studied in a ${\mathrm{CS}}_2$ liquid-core hollow fiber system with a long gain length (2.5 m) by using ≊10-ns laser pulses with a pump intensity range of (${10}^6$–5×${10}^8$ W/${\mathrm{cm}}^2$). The salient features of this stimulated scattering are that the spectral broadening range is very large (≥700 ${\mathrm{cm}}^{\mathrm{-}1}$) and no detectable shift of the spectral maximum or periodical modulation structure is observed. In order to interpret our experimental results, various possible mechanisms and processes are discussed. A model based on stimulated Kerr scattering of anisotropic molecules in liquid is suggested to explain the observation. This model assumes a single-step reorientation of anisotropic molecules induced by an intense optical field.