Influence of Y3+ doping concentration on the structure and optical properties of Pr,Yb,Ho:GYTO polycrystalline powders

Pr,Yb,Ho:GYTO polycrystalline powders with various Y3+ doping concentration were synthesized by the solid-state method. Their structures were determined by the Rietveld refinement to X-ray powder diffraction. The optical spectra of Pr,Yb,Ho:GYTO polycrystalline powders were investigated by absorption and emission measurements at room temperature. With the increase of doping concentration of Y3+, the photoluminescence emission peaks related to 5I6→5I7 show a red shift from 2908 nm to 2915 nm, and a fluorescence emission with the center of 2911 nm was observed when Y3+ doping concentration is 47 at%. The 1200 nm and 2000 nm infrared emissions were also surveyed. Lifetime measurement indicates that the deactivator Pr3+ ions can efficiently decrease the lifetime of the lower level 5I7 of Ho3+. Furthermore, energy-transfer mechanism between in Y3+-Ho3+-Pr3+ was also studied and analyzed.