Preparation and mid-infrared 2.7 µm luminescence property of high content Er3+-doped (Y0.9La0.1)2O3 transparent ceramics pumped at 980 nm

High content Er3+ doped (Y0.9La0.1)2O3 transparent ceramics have been prepared by conventional ceramic process. Absorption spectra, mid-infrared, up-conversion and near-infrared emission spectra of Er3+ pumped at 980 nm have been investigated. The mechanisms of energy transfer processes have been discussed. Large values of Judd-Ofelt parameter Ω2 (5.73 × 10-20 cm2) and spectral quality factor X (3.71) have been obtained. The greatly enhanced green up-conversion emission in the high Er3+ doped sample is considered important for the applications in up-converters. The much enhanced mid-infrared 2.7 µm and up-conversion emissions, as well as the depressed near-infrared 1.5 µm emission demonstrate the efficient population inversion of Er3+:4I11/2 → 4I13/2 in high Er3+-doped ceramics for the 2.7 µm emission. These results suggest that high Er3+-doped (Y0.9La0.1)2O3 transparent ceramics are promising host materials for the applications of mid-infrared lasers and infrared-to-visible up-converters.