High-efficiency fluorescence radiation of Dy³⁺ in alkaline earth borate glasses

Dy³⁺-doped alkaline-earth borate glasses (LKZBSB) with high quantum yield and multifarious emission channels have been fabricated and efficient warm yellowish-white fluorescence is presented under UV light excitation. Judd-Ofelt parameters Ω₂=5.36×10 ^-20 cm², Ω₄=1.46×10^-20 cm² and Ω₆=1.95×10^-20 cm ² indicate a high asymmetrical and covalent environment in the optical glasses. The maximum stimulated emission cross-sections σ_em-max corresponding to the ⁴F_9/2→ ⁶H_15/2, ⁴F_9/2→ ⁶H_13/2, ⁴F_9/2→ ⁶H_11/2 and ⁴F_9/2→( ⁶H_9/2, ⁶F_11/2) transitions are derived to be 2.64×10^-22, 20.07×10^-22, 3.45×10^-22 and 9.31×10^-22 cm², respectively, and the relevant spontaneous emission probabilities A _rad are 174.08, 616.07, 68.95 and 87.10 s^-1. Quantitative characterization reveals that Dy³⁺-doped LKZBSB glasses exhibit a quantum yield as high as 16.65%, confirming that the effectiveness of the warm yellowish-white luminescence in Dy³⁺-doped LKZBSB glasses. Multifarious emission channels and high quantum yield illustrate the great advantages of Dy³⁺-doped LKZBSB glasses in developing fiber-lighting sources, display devices, tunable visible lasers, and optical signal amplifiers.