Lasing potentialities and white light generation capabilities of Dy³⁺ doped oxy-fluoroborate glasses

Oxy-fluoroborate (OFB) glasses doped with different concentrations of Dy³⁺ ions were synthesized through melt quenching technique and characterized by using optical absorption, photoluminescence and decay analysis to understand the lasing potentialities and their utility for white light emitting diodes (LEDs). The XRD spectrum recorded for undoped OFB glass confirms the amorphous nature of the prepared glasses. Judd–Ofelt theory has been applied to the recorded absorption spectra to measure the radiative properties such as transition probability (A_R), radiative lifetimes (τ_R), branching ratios (β_R) and spectroscopic quality factor (χ) for the prominent fluorescent levels. The emission spectra recorded for these glasses gives four emission transitions ⁴F_9/2→⁶H_15/2, ⁶H_13/2, ⁶H_11/2 and ⁶H_9/2 for which effective band widths (Δλ_P), experimental branching ratios (β_exp) and stimulated emission cross-sections (σ_se) are evaluated. To know the lasing potentialities of these glasses, the quantum efficiency (η) of these glasses are measured by recording the decay curves for the prominent emission levels ⁴F_9/2→⁶H_15/2 and ⁴F_9/2→⁶H_13/2. Among the observed emission transitions, a transition at 575 nm (⁴F_9/2→⁶H_13/2) indicates the lasing potentialities. The CIE chromaticity co-ordinates and the confocal photoluminescence images of these glasses further suggests the near white light generation capabilities in principle