K.S. Brewer

Red to blue upconversion in Tm-doped sol–gel silicate glasses

Abstract In thulium-doped glasses derived from the hydrolysis of orthosilicates we worked with different annealing conditions so as to enhance the fluorescence yield. In addition, we observed blue upconverted fluorescence from both the 1 G 4 and 1 D 2 levels of thulium when the glasses were excited with red laser light. Two-step absorption mechanisms with different intermediate levels are responsible for populating the two emitting levels.

Fluorescence line narrowing and decay dynamics in sol–gel glasses containing Eu3+

Abstract Fluorescence line narrowing and emission decay measurements on Eu3+ doped sol–gel glasses have been used to investigate and compare local Eu3+ environments in binary SiO2–TiO2 glasses, SiO2 glasses containing Al3+, and SiO2 glasses without co-dopant. In particular, clustering of rare-earth ions and the effects of annealing temperature on residual hydroxide concentration are studied. The Al and Ti co-doped samples show pronounced line-narrowing implying little energy migration among Eu3+ ions. The 5D0–7FJ fluorescence decays are faster in the Ti glasses.