Abstract

Many persistent spectral hole-burning (PSHB) experiments on various organic glasses and polymers doped with organic molecules reveal that the temperature dependence of the homogeneous linewidth (Γ_h) is T^1.3 at low temperatures (0.3 K ~ 20 K) ^1),2) In contrast to organic molecules, very few PSHB data exist for rare earth ions in inorganic materials while data by fluorescence line-narrowing (FLN) above ~10K are considerably accumulated ³⁾ Macfarlane and Shelby observed PSHB in Pr³⁺- and Eu³⁺-doped silicate glasses and reported that Γ_h of them have a T^1.0 - dependence ^2),4). Similar results were obtained by Van der Zaag et al.⁵⁾. In pure crystals, Γ_h is theoretically expected to have a T⁷ - dependence in the low temperature region and a T² - dependence above the Debye temperature (Raman process) ⁶⁾.

© 1991 Optical Society of America