Near-infrared down-conversion in Pr3+–Yb3+ co-doped transparent glass ceramic containing Ca5(PO4)3F nanocrystals

Pr3+–Yb3+ co-doped transparent oxyfluoride glass ceramics containing Ca5(PO4)3F nanocrystals were synthesized by a melting-quenching method. Spectral analyses demonstrate that Pr3+ and Yb3+ ions are both incorporated into the Ca5(PO4)3F nanocrystals. Near-infrared down-conversion around 1000 nm was observed when the glass ceramics were excited at 435 nm. The maximum actual down-conversion efficiency for 0.3 mol% Pr3+–0.8 mol% Yb3+ co-doped glass ceramic is about 125%.