Comparison of optical parameters and luminescence between Er3+/Yb3+ codoped phosphate glass ceramics and precursor glasses

Er3+/Yb3+ codoped transparent phosphate precursor glasses and glass ceramics have been fabricated and characterized. The formation of ErPO4 and YbPO4 nanocrystals was studied using x-ray diffraction. The intensity parameters, the spontaneous radiative transition probabilities, the branching ratios, and the radiative lifetimes of Er3+ in both glass ceramics and precursor glasses were calculated based on the Judd-Ofelt theory, and the crystallization process in the glass ceramics is confirmed by the optical parameters obtained. Under 975 nm wavelength excitation intense 1.54 μm fluorescence and upconversion luminescence were observed in the glass ceramics, the quantum efficiency of the Er3+4I13/2→4I15/2 transition is 95%, and the transition mechanisms of the upconversion luminescence are due to a two-photon process