Spectroscopic properties of Sm3+ ions in phosphate and fluorophosphate glasses

Spectroscopic properties of Sm3+-doped phosphate and fluorophosphate glasses of the composition (60-x/2) P2O5+15 K2O+(15-x/2) SrO+10 Al2O3+x Sm2O3 (PKSASm) and (54-x/2) P2O5+14 K2O+10 KF+(13-x/2) SrO+9 Al2O3+x SM2O3 (PRFSASm), 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 (Omega(2), Omega(4) and Omega(6)) have been determined using the Judd-Oflet theory, which in turn is used to predict the radiative transition probability (A(R)), radiative lifetime (tau(R)) and branching ratios for the fluorescent (4)G(5/2) level. The higher stimulated emission cross-sections, 12.27 x 10(-22) and 14.12 x 10(-22) cm(2) have been observed for the (4)G(5/2)-> H-6(9/2) transition of PKSASm10 and PKFSASm10, respectively. The non-exponential nature of the decay curves of the (4)G(5/2) level increases with increase in Sm3+ 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. (C) 2013 Elsevier B.V. All rights reserved.