Energy Transfer in Er:CeF₃ Crystals

Two Er:CeF₃ crystals doped with 1.0 and 1.2 wt.% Er₂O₃ and one pure CeF₃ crystal were grown, their absorption and fluorescence spectra at room temperature were measured. Compared with pure crystal, the emission intensity of Ce³⁺ in Er : CeF₃ decreased obviously, it is the sign of energy transfer from 5d state of lattice Ce³⁺ to 4f state of Er³⁺ ions which improves the stimulation emission efficiency of Er³⁺ ions.