Observation of upconversion white light and ultrabroad infrared emission in YbAG:Ln3+ (Ln = Nd, Sm, Tb, Er)

We report on the intense white-light upconversion and ultrabroad infrared (IR) emission for the sol–gel synthesis of Yb3Al5O12 (YbAG):Ln3+ (Ln = Nd, Sm, Tb, Er) following excitation with low-energy near-infrared light (λex = 980 nm). Sufficient cross relaxations and photon avalanches play important roles in the formation of efficient visible and IR broad bands. The brightness of white-light upconversion was 6.2 × 104 cd/m2 at a laser power of 1.47 W, and the IR broad bands (1200–1700 nm) covered all the bands in optical communication media, which indicates that the material might be promising for the development of devices such as white lasers, LEDs, and integrated waveguides.