Fabrication and mid-infrared property of Er:CaF2 transparent ceramics

High doped Er:CaF₂ transparent ceramics (up to 10.0 at.%) were fabricated by hot pressing nanopowders which were synthesized by co-precipitation method. The composition and micrographs of the powders were characterized. The mid-infrared emission spectra and lifetimes of the ⁴I_13/2 energy level of Er:CaF₂ transparent ceramics were investigated for the first time. The mechanisms of energy transfer processes based on the emission spectra of different wavelengths were discussed. The enhanced 2.7 μm emission intensity and the reductions of near-infrared fluorescence lifetimes were observed indicating that the high concentrations of Er³⁺ ions are beneficial to overcome the self-termination effect and realize 2.7 μm laser output. It can be seen from these results that high concentrations Er-doped CaF₂ transparent ceramics can be considered as promising host materials for the applications of mid-infrared lasers.