Studies on optical absorption and photoluminescence properties of Pr~(3+)and Nd~(3+)doped mixed alkali chloroborate glasses

摘要

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_2O_3-xLiCl (30-x)NaCl and 70B_2O_3xLiCl(30-x)KCI (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.