Dy3+/Er3+/Tm3+ tri-doped tellurite glass with enhanced broadband mid-infrared emission

Dy3+/Er3+/Tm3+ tri-doped tellurite glass was synthesized using melt-quenching technology, and the enhanced broadband mid-infrared band luminescence around 3.0 µm was reported for the first time under the excitation of 808 nm laser diode. The broadband mid-infrared luminescence observed in the range of 2600–3200 nm comes from the spectral overlapping of Er3+:2.7 µm and Dy3+:2.84 µm emissions, while the significant enhancement is mainly contributed by the energy transfers from Er3+:4I13/2 to Dy3+:6H11/2, Er3+:4I13/2 to Tm3+:3F4 and Tm3+:3F4 to Dy3+:6H11/2 levels. Compared with Dy3+ single-doped tellurite glass, the peak intensity of this mid-infrared band luminescence in tellurite glass tri-doped with 0.5 mol% Dy2O3, 0.5 mol% Er2O3 and 1.0 mol% Tm2O3 increases by about 214%. Additionally, the spectroscopic properties of Dy3+ ions were investigated by applying Judd-Ofelt theory and the energy transfer mechanism was analyzed to understand the enhanced broadband luminescence phenomena. The obtained results reveal that Dy3+/Er3+/Tm3+ tri-doped tellurite glass is a promising lasing medium for 3.0 µm band mid-infrared broadband photonic devices.