Influence of gallium on infrared luminescence in Er3+ doped Yb3Al5−yGayO12 films grown by the liquid phase epitaxy

Erbium (Er3+) doped ytterbium garnet Yb3Al5−yGayO12 (y=0, 0.55 and 1.1, YbAGG) thick films were grown by the isothermal liquid phase epitaxy method (LPE) on LuAG or YAG substrates. The influence of gallium on the photoluminescent properties of Er3+ is presented in this paper. Room temperature transmission and emission spectra were measured for the 0.5 at% Er3+:YbAGG films with a different doping level of Ga. Also Er3+:Yb3Al3.9Ga1.1O12 (y=1.1) films with a different doping level of erbium (0.5, 1 and 2 at%) were tested. The presence of gallium significantly affects the fine splitting and total intensity of erbium emission in an infrared region (the transition 4I13/2→4I15/2). Even at the highest doping level of erbium (2 at%), no up-conversion luminescence was observed, resulting in a maximum efficiency of the infrared emission. The lifetime of luminescence at 1530 nm was studied for all samples.