Spectroscopic properties of Dy 3+ ions in NaF–B 2O 3–Al 2O 3 glasses

Abstract

This paper reports the optical properties of Dy 3+ in sodium fluoroborate glasses of the type XNaF·(89 − X)B 2O 3·10 Al 2O 3·1Dy 2O 3 (where X = 8, 12, 16, 20 and 24). Judd–Ofelt intensity parameters ( Ω 2, Ω 4, Ω 6) are derived from the absorption spectra. The Judd–Ofelt theory has been applied to interpret the local environment of Dy 3+ ions and bond covalency of RE–O bond. These parameters have been used to calculate radiative transition probabilities ( A rad), lifetimes ( τ R) and branching ratios ( β R) for the excited level 4F 9/2. The predicted values of τ R are compared with the measured values for 4F 9/2 level for five glass compositions (Glass (A–E)). The stimulated emission cross-section σ( λ P) are also evaluated for the 4F 9/2 → 6H J ( J = 11/2, 13/2, and 15/2) transitions.