Up-conversion and near-infrared luminescence in Er3+ -doped La2O3-PbO-B2O3-TeO2 glasses for the generation of fibre amplifiers and green LED applications
A. Madhu, Ch. Basavapoornima, Sahar Ahmed Idris, N.S. Abd EL‐Gawaad, Vadiraj B Tangod, N. Srinatha
Abstract
In this work, we demonstrate the influence of Er 3+ ions on the spectroscopic properties of 5La 2 O 3 -15PbO-(50- x )B 2 O 3 - x Er 2 O 3 -30TeO 2 glasses doped with x = 0.1, 0.5, 1.0, 2.0 & 3.0 mol% of Er 3+ were prepared with the melt-quenching method. The structural, fluorescence and decay time properties were examined, and the theoretical model, JO, Mc , and FL theory, was utilised to confirm the experimental findings. It is evident from XRD results that the glasses do not possess a well-defined crystalline structure. Instead, they exhibit a random arrangement of atoms and molecules, indicating an amorphous characteristic. JO analysis yields the stimulated-emission cross-section (2.12 ×10 −20 for LPBTE1 glass, which is highest among other prepared glasses) & intensity parameters (Ω 2,4,6 ) show Ω 2 > Ω 6 > Ω 4 trend indicating the covalency nature. Predominant luminescence in the NIR region, emission peaked at 1537 nm was observed, which was ascribed to the 4 I 13/2 ⟶ 4 I 15/2 transition. The temporal decay rate decreased from 0.83 ms to 0.27 ms with an increase in the concentration of Er 3+ from 0.1 to 3 mol%, which is due to the self-quenching action of the cross-relaxation channels. Furthermore, using Mc-Cumber's theory the peak values for the emission and absorption cross-sections are evaluated and found in good agreement with each other. The gain profile demonstrates more than 40% population inversion between 1530 and 1610 nm in the C +L band. In addition, the up-conversion of 4 S 3/2 ⟶ 4 I 15/2 transitions at 544 nm exhibits green emission shows two-photon absorptions. Overall, the investigated results demonstrate that the prepared Er 3+ -doped La 2 O 3 -PbO-B 2 O 3 -TeO 2 glasses are the best choice for optical fibre applications.