Abstract

Rayleigh-Brillouin scattering and low frequency Raman scattering were studied in several fluoride and oxide glass samples with temperature as a variable. The temperature varied from room temperature to beyond the glass transition region. The Landau-Placzek ratio and the Brillouin shifts as a function of temperature in the glass transition region showed anomalous scattering phenomena in this region. For the Raman scattering the frequency regime studied is from close to the exciting line to ~200 cm⁻¹ with the temperature range extending beyond the glass transition region. The intensity and the line width of the most dominant spectral line, the boson peak, was studied extensively and was interpreted in its relation to the extent of the density fluctuations in glass. The above results were interpreted as evidence of the physical origin of the non-exponential character of the structural relaxation kinetics and their relationship to thermally induced nanoscale inhomogeneities.

© 1993 Optical Society of America