Upconversion and infrared luminescences in Er3+/Yb3+ codoped Y2O3 and (Y0.9La0.1)2O3 transparent ceramics

Er3+ and Yb3+ codoped Y2O3 and (Y0.9La0.1)2O3 transparent ceramics were fabricated by the conventional ceramics processing with nanopowders. Compared to Er/Yb:Y2O3, Er/Yb:(Y0.9La0.1)2O3 ceramics had higher transmittance. Intense upconversion (UC) and infrared emission (1543 nm) were observed under excitation of 980 nm. According to three intensity parameters Ω2, Ω4, and Ω6 fitted by the Judd–Ofelt theory, the spectroscopic quality parameters (X), radiative lifetimes (τrad), and emission cross-sections (αem) were determined. Er/Yb:(Y0.9La0.1)2O3 ceramics owned broader peaks and longer lifetime (12.3 ms) at 1548 nm due to the glass-like structure of (Y0.9La0.1)2O3 ceramics. The results showed Y2O3 and Y1.8La0.2O3 transparent ceramics are promising gain media for developing the solid-state 1.5 μm optical amplifiers and tunable UC lasers.