Spectral diffusion induced by the spatial motion of point perturbers

✍ Scribed by J. Kikas; J.L. Skinner

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 857 KB
• Volume: 230
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)01225-3

✦ Synopsis

The usual theory of spectral diffusion involves a chromophore coupled to a collection of flipping two-level systems. A somewhat different approach is taken, assuming instead that spectral diffusion is due to the spatial motion of point perturbers. We derive a general expression for the spectral diffusion kernel, and provide explicit analytic results that are valid for small displacements of the perturbers. For a model where the chromophore-Thurber interactions are dipolar and each perturber has two spatial positions the theory produces in a natural way the often observed T"13 temperature dependence of hole widths in glasses, and at the same time predicts a weakly non-Lorentzian hole shape. Our results also point to novel spectroscopic possibilities for determining the spatial diffusion constant and density of defects in crystals.