Spectroscopic properties of Yb3+/Ho3+:Lu1.5Y1.5Al5O12 crystals

Yb3+ and Ho3+ co-doped Lu1.5Y1.5Al5O12 (abbr. as Yb/Ho:LuYAG) crystals were grown using Czochralski method, and their spectroscopic properties were systematically studied. The effect of the doping concentration of Yb3+ on the spectroscopic performances were discussed comprehensively, and it was found that the 1 at% Ho3+, 5 at% Yb3+:LuYAG crystal shows better spectral properties. For example, the sensitized ion Yb3+ can transfer 64.9 % of its own energy to Ho3+ to achieve effective pumping of Ho3+ and thus obtain the intense infrared emissions with peak at 2090 nm. Furthermore, under the pumping of 937 nm, the green, red and infrared waveband emissions with peaks at 558, 667 and 756 nm were observed in it, and the red emission is much stronger than the other two emissions. The results show that 1 at% Ho3+, 5 at% Yb3+:LuYAG crystals are excellent gain media for realizing up-converted visible lasers and infrared lasers in the ∼2.09 µm band.