Optical properties of peralkaline aluminosilicate glasses doped with Sm3+

Abstract

Enhancing the fluorescence and thermo-mechanical properties of rare-earth doped aluminosilicate glasses (AS) by modifying the chemical composition with different alkaline earth oxides opens new opportunities for their application as optical devices. This paper provides a study on 1 × 1020 ions/cm3 Sm3+ doped aluminosilicate glasses, with the network modifier oxides BaO, SrO, CaO, MgO (35 mol%), Al2O3 (10 mol%) and SiO2 (55 mol%), denoted as BaAS, SrAS, CaAS and MgAS, prepared by the melt quench technique. Based on the measured UV–visible and NIR absorption spectra, the Judd-Ofelt parameters Ωλ, (λ = 2, 4, 6) were evaluated to predict the radiative properties of Sm3+ ions such as radiative transition probabilities (Arad), radiative lifetimes (τrad) and branching ratios (βR). By using the Füchtbauer-Ladenburg (FL) formula, the gain cross sections were calculated from the stimulated emission cross sections. The glass BaAS has the highest value of Ω2 which corresponds to a high asymmetry at the rare earth sites and the glass MgAS has the highest values of Ω4 and Ω6 which corresponds to a high rigidity and a low optical basicity of the glass. The same glass has the highest quantum efficiency and the highest gain cross section values of the investigated glasses. On the other hand, the glass BaAS has the smallest efficiency and gain cross section, however, it provides the lowest glass transition temperatures which would be beneficial for the production of high-quality glass. Raman spectra of the AS glasses show a broader variation of Qn species and an increasing depolymerization for glasses with network modifier ions of larger ionic radii.