Homogeneous fluorescence linewidths for amorphous hosts

Abstract

A contribution to the homogeneous linewidth of optical transitions in amorphous hosts is calculated. The microscopic process is diagonal in the phonon interaction with two level systems (TLS) common to amorphous materials, and diagonal in the coupling between TLS and the optical center. The model predicts an optical homogeneous linewidth proportional to the square of the temperature at low temperature.