Optical absorption and emission properties of Pr3+ and Er3+ in lithium cesium mixed alkali borate glasses

This article presents the optical absorption and emission properties of Pr3+ and Er3+ in mixed alkali borate glasses of the type 68B2O3·xLi2O·(32-x)Cs2O (where x=8, 12, 16, 20 and 24). The variation of Judd-Ofelt intensity parameters (Ωλ), the peak wavelength of the hypersensitive transitions, radiative transition probabilities (Arad) and peak emission cross-sections (σp) with x in the glass matrix have been discussed in detail. The changes in position of hypersensitive transition and intensity parameters with x are correlated to the structural changes in the host matrix. The estimated radiative lifetimes (τR) of certain excited states of both Pr3+ and Er3+ in lithium cesium mixed alkali borate glasses are reported. Branching ratios (β) and integrated absorption cross-sections (Σ) for certain important transitions are presented. Peak stimulated emission cross-sections (σp) are calculated for the observed emission peaks of Pr3+ and Er3+ ions in this glass matrix.