SrLaGaO4 crystals is given. Upconverted, ultraviolet emission from the 3D 3 level under cw
647nm excitation at room temperature was observed. Excitation of the 5F 5 level,
corresponding to the 5I 8→ 5F 5 transition, leads to intense emission from the 5I 7, 5I 6, 5F 5,
5S 2, 5F 3, 3G 5 and 3D 3 levels. Based on the energy level diagram of Ho3+, the pump
intensity dependencies and experimental time dependencies of the observed emissions, an …