Intense red upconversion luminescence from Tm3+/Yb3+ codoped transparent glass ceramic.

Tm3+/Yb3+ codoped transparent glass ceramic containing β-PbF2 nanocrystals was successfully prepared. After thermal treatment, emissions from the state of Tm3+ excited by 980 nm laser were greatly quenched by cross relaxation and the 700 nm luminescence from Tm3+:3F2,3→3H6 transition was strongly enhanced. A nearly monochromatic red luminescence band was observed. Based on the luminescence decay curves and Judd-Ofelt analysis, the strengthened cross relaxation played an important role in such phenomenon.