Preparation and characterization of Er3+-doped TeO2-based oxyhalide glasses

Abstract Bulk oxyhalide glasses have been prepared in the TeO 2 –ZnO–ZnX 2 and TeO 2 –PbO–PbX 2 systems (X=Cl, Br, I) and the corresponding glass-forming regions have been determined. Their density and characteristic temperatures were also determined. The glass-forming regions increased in the direction I → Br → Cl and were largest for the zinc-tellurite compositions. For the TeO 2 –ZnO–ZnCl 2 system, compositions with 20 mol% ZnO presented the highest glass-forming ability and had high thermal stability and good infrared transmittance. The progressive replacement of TeO 2 by ZnCl 2 improved the optical quality of the glasses, as well as their thermal stability, but they became more hygroscopic. Erbium chloride was added to two base glass compositions, 40TeO 2 –20ZnO–40ZnCl 2 and 60TeO 2 –20ZnO–20ZnCl 2 (in mol%) and bulk glass samples could be obtained with additions of up to 10 mol% ErCl 3 . Photoluminescence measurements of the erbium-doped glasses, at 1.5 μm, showed highest fluorescence intensity for the 60TeO 2 –20ZnO–20ZnCl 2 compositions, especially with 3 mol% ErCl 3 with a corresponding metastable level lifetime of ∼6 ms. Higher concentrations of erbium caused a decrease of both properties.