Improved communication band fluorescence in Ga2O3-based glasses via containerless solidification synthesis

Designing and developing functional glasses with high efficiency and flexible wideband near-infrared emission tunability is of great research interest for optical communications. Here, strategies of composition optimization and new synthesis technique are employed to effectively regulate rare-earth ions photoluminescence. A series of Er3+-doped(up to 12 mol%) Ta2O5–La2O3–Ga2O3 glasses are fabricated via a levitation melting technique and exhibit small hydroxyl absorptions, wide transparency range, high refractive indices(nd ≥ 2.038), irradiation- and thermal stability (Tg > 868 °C). Upon 980 nm pumping, the 1.5 μm emission intensity reaches the highest value at 2.5 mol% Er2O3 with a bandwidth of 112 nm. Strikingly, the fluorescence lifetime, absorption and emission cross-section and largest gain coefficient of glass with x = 2.5 at 1.5 μm are evaluated to be 4.37 ms, 16.7 × 10−21 cm2, 11.8 × 10−21 cm2 and 6.43 cm−1, respectively. Additionally, structural and temperature stability properties are also characterized. Possible mechanisms related to the reduction in quantum-yield and lifetime are elaborated in detail. Glass uniformity is creatively confirmed by the micro-area fluorescence spectra for the first time. This exploration of high content doping strategy for achieving high-performance glasses may extend the possible versatile applications, and provide feasible design insights into engineering more multi-functional materials with programmable features.