Improving luminescence behavior and glass stability of tellurium-doped germanate glasses by modifying network topology

Broadband near-infrared (NIR) luminescent materials are of great interest for their potential application in optical communication, remote sensing, imaging, and homeland security. Tellurium (Te) doped glasses were recently recognized as such a promising candidate due to their broadband NIR emission (700-1700 nm). However, the achievement of Te-doped glasses with high luminescence efficiency and glass stability (GS) remains a daunting challenge. Here, the luminescence behavior and GS of Te-doped germanate glasses are manipulated by tailoring the glass network topology. Te NIR luminescence is enhanced by tailoring topological cages in germanate glass network structure through varying glass network modifiers. Meanwhile, the GS of potassium germanate glass is significantly enhanced due to increased network connectivity caused by the co-introduction of alkaline earth oxides. Finally, NIR luminescence intensity of the glass was further enhanced by optimizing the doping concentration of TeO2. The findings here could contribute to designing Te-activated glasses with improved performance for application in optical amplifiers and tunable fiber lasers.