Efficient frequency upconversion of Tm3+ ions in Yb3+ doped barium-thorium fluoride glass

Abstract

If infrared light can be efficiently changed to visible light it would have important implications for optical detection and display devices. In this paper the efficiency of the two-photon upconversion process between Yb3+ and Tm3+ ions in BaF2/ThF4 heavy metal fluoride glass is investigated as a function of Tm3+ concentration and temperature. It is found that for the concentration of 0.05-mol % TmF3 and a projected incident infrared intensity of 1 W/cm2, the projected efficiency at 300 K would be 1.2%.