Studies on optical absorption and photoluminescence properties of Pr3+ and Nd3+ doped mixed alkali chloroborate glasses

Abstract This article presents the optical absorption and emission properties of Pr 3+ and Nd 3+ doped two different mixed alkali chloroborate glass matrices of the type 70B 2 O 3 · x LiCl·(30 −  x )NaCl and 70B 2 O 3 · x LiCl·(30 −  x )KCl ( x  = 5, 10, 15, 20 and 25). The variation of Judd–Ofelt parameters ( Ω 2 , Ω 4 and Ω 6 ), total radiative transition probabilities ( A T ), radiative lifetimes ( τ R ) and emission cross-sections ( σ p ) with the variation of alkali contents in the glass matrix have been discussed in detail. The changes in the peak wavelengths of the hypersensitive transition and intensity parameters with x are correlated to the structural changes in the host matrix. The estimated radiative lifetimes of certain excited states of Pr 3+ and Nd 3+ in these two glass matrices are reported. Peak stimulated emission cross-sections ( σ P ) are reported for the observed emission transitions of Pr 3+ and Nd 3+ ions. Branching ratios ( β ) of the observed emission transitions obtained from the Judd–Ofelt theory are compared with the values obtained from the emission spectra.