OBSERVATION OF RESONANT HYPER-RAMAN SCATTERING OF LIGHT IN A CDS CRYSTAL USING A TUNABLE OPTICAL PARAMETRIC OSCILLATOR

The first observation of resonant hyper-Raman scattering (RHRS) of lig ht that involves phonon polaritons is reported. The intensity of scatt ering and the frequency of polaritons involved in scattering are obser ved to increase as the quantum energy of the scattered light approache s the energy of the forbidden gap in a CdS crystal. Spectra of RHRS fr om optical phonons in a CdS crystal are recorded and interpreted for t he first time by means of a tunable laser. As a source of tunable radi ation (0.94-1.04 mu m), an optical parametric oscillator with a KTP cr ystal was used. Such a parametric oscillator is an efficient source of tunable radiation for the investigation of a broad class of semicondu ctor materials using the method of hyper-Raman scattering.