Influence of mixed alkalis on spectroscopic parameters of Sm 3+, Dy 3+ doped chloroborate glasses

Abstract

This article reports the effect of mixed alkalis on the optical absorption and emission spectra of Sm 3+ and Dy 3+ doped chloroborate glass matrices of the compositions 69.5B 2O 3 xLiCl(30 − x)NaCl0.5R 2O 3 and 69.5B 2O 3 xLiCl(30 − x)KCl0.5R 2O 3 (where R = Sm and Dy and x = 5, 10, 15, 20 and 25). Using Judd–Ofelt theory, the spectral intensities and Judd–Ofelt intensity parameters ( Ω 2, Ω 4 and Ω 6) were obtained from the measured absorption bands of the spectra. Using these intensity parameters, total radiative transition probabilities ( A T), radiative lifetimes ( τ R), branching ratios ( β) and peak emission cross-sections ( σ P) were obtained for the two rare earth ions in these two glass matrices. Variation of these parameters with x in the glass matrix has been discussed. It is found that for Sm 3+ ion, the transition, 4G 5/2 → 6H 9/2 shows highest emission cross-section and is maximum at x = 10 mol% in lithium–sodium and at x = 20 mol% in lithium–potassium glass matrices. For Dy 3+ ion, the transition, 4F 9/2 → 6H 13/2 shows highest emission cross-section and is maximum at x = 20 mol% in lithium–sodium and at x = 10 mol% in lithium–potassium glass matrix.