Investigation of luminescence and laser transition of Dy³⁺ in Li₂O-Gd₂O₃-Bi₂O₃-B₂O₃ glasses

The aim of this study is to develop Li₂O-Gd₂O₃-Bi₂O₃-B₂O₃ glass doped with different concentration of Dy³⁺ ions by melt quenching technique for different applications in photonics and laser devices. From the experimental oscillator strength (f_exp) of the absorption spectra the JO intensity parameters () have been calculated, and by using these JO intensity parameters various radiative parameters were calculated. By using JO theory the radiative transition probability (A_R), radiative lifetime (τ_R) and branching ratio (β_R) for Dy³⁺ ion have been found. A decrease in lifetimes of the prepared glass by increasing concentration of Dy³⁺ is because of the energy transfer through cross relaxation and resonant energy transfer channels in the present glass matrix. Using experimental and calculated lifetimes, the quantum efficiency (η) and non-radiative relaxation rates (W_NR) of ⁴F_9/2 excited state have been calculated. From emission spectra, effective bandwidths () and emission stimulated emission cross section were found for ⁴F_9/2 → ⁶H_J (J = 15/2, 13/2, 11/2 and 9/2). Chromaticity results revealed that the CCT values of the LGBiBDy glass samples are in between to those of day light and commercial white light LED sources. Further investigations are under way for the optimization of dopant concentration in the Li₂O-Gd₂O₃-Bi₂O₃-B₂O₃ glass.