Enhanced structural and spectroscopic properties of Er3+-doped TeO2-Ta2O5-ZnO glasses for 2.7 μm fiber lasers

Tellurite-based glass composed of TeO ₂-Ta ₂O ₅ -ZnO (labeled as TTZ) is explored as the host material for a potential 2.7 μm fiber laser. It is found that the glass-forming region, structural and physical properties of TTZ glass undergo considerable changes when platinum crucible are adopted to prepare glass instead of alumina one. Especially, the Er ³⁺-doped TTZ glass that melted in platinum crucible exhibits relatively larger absorption and emission cross-sections at 2.7 μm than that of alumina one. Further studies show that an enhanced 2.7 μm luminescence can be achieved from the heavily Er ³⁺ -doped TTZ glass, the absorption and emission cross-sections, figure of merit and maximum gain coefficient of Er ³⁺-doped TTZ-Pt glasses at 2.7 μm are calculated to be 0.91 × 10 ⁻²⁰ and 1.01 × 10 ⁻²⁰ cm ², 3.18 × 10 ⁻²⁴ cm ²·s and 2.25 cm ⁻¹, respectively, indicating that the Er ³⁺-doped TTZ glass may be a promising candidate host for mid-infrared fiber lasers.