Variations in Homogeneous Fluorescence Linewidth and Electron-Phonon Coupling within an Inhomogeneous Spectral Profile.

摘要

The fluorescence line narrowing technique (FLN) is used to determine the homogeneous width of the 5D(0) to 7D(0) resonance fluorescence line of Eu(3+) in an amorphous silicate matrix as a function of laser excitation wavelength and temperature (200-350 K). A smooth increase in delta nu sub hom is observed as the excitation wavelength is decreased across the inhomogeneous profile (excitation of sites of progressively higher average crystal field. The combined temperature and excitation wavelength dependence identify the broadening mechanism as a two-phonon Raman scattering process and suggest that the observed increase of delta nu sub hom with increasing excitation energy is due to stronger electron-phonon coupling at sites of stronger crystal field. (Author)