The transparent oxyfluoride glass ceramics containing Ba Gd F5 nanocrystals were prepared with a composition of 42 Si O2-12Na2O-16Al2O3-24 Ba F2-4Gd2O3-2Ce F3（mol.%） by thermal treatment technology. The typical DSC curve, X-ray diffraction（XRD） and transmission electron microscopy（TEM） patterns were measured. The transmission spectra and luminescent properties were investigated. The decay times of the Gd^3＋ ions at 312 nm excited with 275 nm for the Ce^3＋ ions doped glass and glass ceramics specimens and the energy transfer process between Gd^3＋ ions and Ce^3＋ ions were also studied. The XRD analysis and the TEM images confirmed the generation of the spherical Ba Gd F5 nanocrystals. Compared with the PG specimen, the intensity of the luminescence spectra of the glass ceramics specimens was apparently enhanced with the heat treatment temperature increasing, and a blue shift in the excitation spectra and the emission spectra of glass ceramics specimens was obviously observed. In the fluorescence decay curves of the Gd^3＋ ions, it could be obviously observed that the fluorescent intensity decays in the Ce^3＋ ions doped glass and glass ceramics specimens decreased rapidly with the increase of the heat treatment temperature. In addition, the energy transfer efficiency from Gd3＋ions to Ce^3＋ ions was also calculated.
An efficient near-infrared （NIR） quantum cutting （QC） in Tm3＋ and Yb3＋ co-doped phosphate glasses was demonstrated, which involved the emission of two NIR photons from an absorbed visible photon via a cooperative energy transfer （CET） from Tm3＋ to Yb3＋ ions. Judd-Ofelt （J-O） theory was used to calculate the intensity parameters （ 2 , 4 , 6 ）, the radiative transition rates （Ar ）, and radiative transition lifetime （τ rad ） of Tm3＋ . Based on Inokuti-Hirayama＇s model, the energy transfer processes were studied and results indicated that the energy transfer of the electric dipole-dipole （Edd） was dominant in this system. Quantum efficiency related to Yb 3＋ concentration was calculated, and the maximum QE efficiency reached 169.8%.
