摘要 : The hyper-Raman scattering (HRS) is a nonlinear optical process where a phonon creation and an emission of scattered photon occur due to absorption of two photons of incident radiation. Of special interest is the HRS for two-photo... 展开 The hyper-Raman scattering (HRS) is a nonlinear optical process where a phonon creation and an emission of scattered photon occur due to absorption of two photons of incident radiation. Of special interest is the HRS for two-photon excitation near the energy gap of semiconductors because the resonant increase in the hyper-Raman efficiency substantially extends experimental possibilities. The resonant HRS was reported in a number of semiconductor crystals [1-8]. In a CdS crystal the hyper-Raman scattering by longitudinal optical (LO) phonons was experimentally investigated at the different wavelengths of exciting radiation [3]. A striking enhancement of the hyper-Raman signal was found in ZnSe when the doubled energy of incident photons approached to resonance with the 2P exciton state [4-5]. The resonant HRS by longitudinal and transverse optical phonons was observed in TiO{sub}2 where the one-photon dipole transition is forbidden [6-7]. In conditions of two-photon resonance with the 1S yellow exciton the scattering by (Γ{sub}12){sup}- phonon in Cu{sub}2O was reported [8]. But the phenomenon of particular interest was found in CdS where the appearance of the intensive 2LO line in hyper-Raman spectra was detected when the doubled energy of incident photons was close to the 1S exciton energy level [3]. 收起