Resonant Brillouin scattering in ZnSe

Abstract

Resonant Brillouin scattering in ZnSe has been investigated at room temperature and at 77 K by using the amplified acoustical-domain injection method. The observed dispersion curves have shown resonant cancellation and enhancement in the region near the fundamental absorption edge, and new maxima have been found in the scattering cross sections very close to the ground-state exciton energy region. The Brillouin-scattering cross section is found to depend strongly on the lifetime-broadening effect of the intermediate electronic states near the resonance region. The dispersion of the Brillouin-scattering cross section has shown good agreement with the theoretical analysis based upon Loudon's light scattering theory, assuming the virtual Wannier-Mott exciton transitions when the lifetime-broadening effect is taken into account. The dispersion curves of the photoelastic constants, $p_{11}-p_{12}$ and $p_{44}$, have been determined from the piezobirefringence analysis, where the lifetime-broadening effect is also taken into consideration as in the Brillouin-scattering analysis.