Intense ultraviolet emission from Tb3+ and Yb3+ codoped glass ceramic containing CaF2 nanocrystals

Abstract

A transparent Tb3+ and Yb3+ codoped oxyfluoride glass ceramic containing CaF2 nanocrystals was developed. This glass ceramic showed an intense ultraviolet emission at 381nm due to the G65, D35→F67 transitions of Tb3+ ion when excited with a 974nm laser at room temperature. The observed intense ultraviolet emission could be attributed to the change of ligand field of Tb3+ and Yb3+ ions due to the incorporation of some Tb3+ and Yb3+ ions into CaF2 nanocrystals, and the resulting increased branching ratio of the transitions and longer lifetime of D45 level of Tb3+ in the glass ceramic.