Polarization properties of quasielastic light scattering in fused-silica optical fiber

Abstract

Polarized and depolarized components of the quasielastic light-scattering spectrum of fused-silica optical fiber have been measured in the frequency range 100 kHz to 100 MHz at temperatures from 10 to 293 K. The depolarization ratio was found to be 0.14±0.03. In the backscattering geometry both polarization components are seen to obey an inverse-power-law frequency dependence. Both the temperature and frequency dependence are consistent with a model that assumes thermal activation of structural relaxations which have a wide distribution of relaxation-time constants. In the forward direction, an additional polarized component with the same temperature dependence appeared.