Enhanced blue and broadband near-infrared emission of Pr3+/Yb3+ co-doped PbF2 single crystal

High quality Pr3+ single-doped PbF2 and Pr3+/Yb3+ co-doped PbF2 single crystals were grown by temperature gradient technique (TGT). By co-doping Yb3+ ion as Pr3+ ions sensitizer, the visible light emission can be regulated and the largest luminescence branching ratio can be switched from red-orange to blue-green light. Besides, when Pr3+ ions doping concentration is as low as possible, the blue light self-absorption effect can be weakened, which is beneficial to high-efficiency blue laser output. Moreover, the broad band emission around 1.3 μm from 1G4 energy level can be observed in the Pr3+/Yb3+:PbF2 crystal with the low maximum phonon energy for the first time. Absorption, emission spectra and luminescence mechanism are well analyzed by the energy transfer process and J-O theory. The laser upper energy level lifetime of Pr3+ ions has a great increase by Yb3+ ion effect. These advantageous spectroscopic characteristics show that the Pr3+/Yb3+:PbF2 crystal might be potential laser gain materials for blue-green and ∼1.3 μm near-IR laser operation.