Enhanced up-conversion and 2.7 µm luminescence of Er3+/Yb3+ co-doped yttrium lanthanum oxide transparent ceramics pumped at 980 nm

The optical properties of Er3+ ions in Er3+/Yb3+ co-doped yttrium lanthanum oxide transparent ceramics prepared by conventional ceramic processing have been investigated as a function of the rare-earth doping content. Absorption spectra, mid-infrared, near-infrared and up-conversion luminescence spectra and decay curves have been measured exciting at 980 nm. Large absorption cross-section of Yb3+ ion (1.6 × 10-20 cm2) and the enhanced mid-infrared, near-infrared and red up-conversion luminescence demonstrate that Yb3+ ion is a promising sensitizer to efficiently activate Er3+ ion for 2.7 µm emission. Large Judd-Ofelt parameter Ω2 and spectroscopic quality factor value around 5.73 × 10-20 cm2 and 6.22 respectively have been obtained, as well as higher emission cross-section for 2.7 µm emission (2.18 × 10-20 cm2). These results indicate that the Yb3+/Er3+:(Y0.9La0.1)2O3 transparent ceramic is a predominant host material for MIR lasers and infrared-to-visible up-converters.