Resonant Brillouin Scattering and Piezobirefringence in ZnS

Abstract

We have measured the resonant Brillouin scattering in cubic and polytype ZnS at 300 K and 77 K using two kinds of transverse acoustic waves excited by the acoustic domain injection technique. The observed spectra have been found to agree well with the resonant light scattering theory when the lifetime broadening effect is taken into account. Measurements of the piezobirefringence have been performed to obtain dispersion of the elasto-optical constants in the same crystals, and the results are in good agreement with those deduced from the resonant Brillouin scattering data when the ω⁴ dependence of the Brillouin-scattering cross sections is taken into account. Combining the Brillouin scattering data with the piezobirefringence data we are able to determine the spectral dependence of elasto-optical constants P₁₁−P₁₂ and P₄₄ in both cubic and polytype ZnS in the photon energy region 1.8 to 3.7 eV at 300 K.