Absorption and fluorescence studies of Sm3+ ions in lead containing sodium fluoroborate glasses

Lead containing calcium zinc sodium fluoroborate glasses (LCZSFB) with molar composition of 20PbO+5CaO+5ZnO+10NaF+(60−x) B2O3+x Sm2O3, (x=0.1, 0.25, 0.5, 1.0 and 2.0 mol%) were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. Judd–Ofelt theory was applied to the experimental oscillator strengths to evaluate the phenomenological J–O intensity parameters Ωλ (λ=2, 4 and 6). Using the J–O intensity parameters as well as from the emission and decay measurements, various radiative parameters such as transition probabilities (AR), radiative lifetimes (τR), measured lifetimes (τm), calculated branching ratios (βR), measured branching ratios (βm), effective bandwidth (Δλeff) and stimulated emission cross sections σ(λp) have been calculated for the excited 4G5/2 luminescent level. The nature of decay curves of 4G5/2 level for different Sm3+ ion concentrations in all LCZSFB glasses has been analyzed and the lifetimes are noticed to decrease with increase of concentration. The concentration quenching has been attributed to the energy transfer through the cross-relaxation between Sm3+ ions. Based on these results, the utility of Sm3+ ions doped lead containing fluoroborate glasses as laser active materials in the visible region is discussed.