Spectroscopic properties of Sm3 + ions in phosphate and fluorophosphate glasses

摘要

Spectroscopic properties of Sm~(3 +)-doped phosphate and fluorophosphate glasses of the composition (60 - x / 2) P_2O _5 + 15 K_2O + (15 - x / 2) SrO + 10 Al_2O _3 + x Sm_2O_3 (PKSASm) and (54 - x / 2) P _2O_5 + 14 K_2O + 10 KF + (13 - x / 2) SrO + 9 Al_2O_3 + x Sm_2O_3 (PKFSASm), where x = 0.1, 0.5, 1.0, 2.0, 4.0 and 6.0 mol%, have been investigated. The oscillator strengths and the intensity parameters (Ω_2, Ω_4 and Ω_6) have been determined using the Judd-Oflet theory, which in turn is used to predict the radiative transition probability (A R), radiative lifetime (τR) and branching ratios for the fluorescent ~4G_(5/2) level. The higher stimulated emission cross-sections, 12.27 × 10~(- 22) and 14.12 × 10~(- 22) cm~2 have been observed for the 4G 5/2 → ~6H_(9/2) transition of PKSASm10 and PKFSASm10, respectively. The non-exponential nature of the decay curves of the 4G5/2 level increases with increase in Sm~(3 +) ion concentration accompanied by decrease in lifetime. The non-exponential decay curves have been best fitted to the generalized Yokota-Tanimoto model indicating that the energy transfer among optically active ions is through dipole-dipole interaction.