The yellow spectral performances of Dy3+: BaF2 and Dy3+/RE3+(RE3+ = Gd3+, Y3+, Lu3+): BaF2 crystals

Abstract

2 at.% Dy3+: BaF2 and 2 at.% Dy3+/2 at.% RE3+(RE3+ = Gd3+, Y3+, Lu3+): BaF2 single crystals were grown by the Bridgman-Stockbarger method, and characterized by absorption, visible emission, and fluorescence decay curves. Also, relying on the excitation and emission spectra, decay curves at low temperature (77 K) for Dy3+: BaF2 and Dy3+/RE3+(RE3+ = Gd3+, Y3+, Lu3+): BaF2 crystals have been measured. We found that Dy ions have at least three lattice sites in BaF2 crystal, and the lattice sites of Dy3+ ions can be reduced by co-doping with Gd3+, Y3+ or Lu3+ ions, where Dy3+: BaF2 and Dy3+/RE3+(RE3+ = Gd3+, Y3+, Lu3+): BaF2 single crystals can be considered as quasi-single lattice crystals. From visible fluorescence spectra, it was found that co-doping Gd3+ will increase the emission intensity of yellow light by 20 times, co-doping Y3+ will increase the emission intensity of yellow light by 30 times, and co-doping Lu3+ will increase the emission intensity of yellow light by 25 times. The calculated absorption cross-section, emission cross-section, and fluorescence lifetimes indicate that Dy3+: BaF2 and Dy3+/RE3+(RE3+ = Gd3+, Y3+, Lu3+): BaF2 crystals especially, Dy3+/Y3+: BaF2 crystals are suitable to achieve yellow laser output.