QUASI-ELASTIC SCATTERING IN GLASSES AND ITS RELATION TO SOUND-ABSORPTION

The quasi-elastic Raman scattering in SiO2 and PS glasses is analyzed in the framework of the model of a damped oscillator. The model ascrib es the quasi-elastic contribution to the scattering of light on damped vibrations which have a quasi-elastic part in their response function . With additional assumption that the vibrations around the boson peak are damped by the same process as the acoustic waves, a good agreemen t is obtained between acoustic attenuation data and QES spectra in SiO 2 and polystyrene both on a qualitative and a quantitative level.