Spectroscopic properties of Sm 3+ -doped phosphate and fluorophosphate glasses of the composition (60−x/2) P 2 O 5 +15 K 2 O+(15−x/2) SrO+10 Al 2 O 3 +x Sm 2 O 3 (PKSASm) and (54−x/2) P 2 O 5 +14 K 2 O+10 KF+(13−x/2) SrO+9 Al 2 O 3 +x Sm 2 O 3 (PKFSASm), where x=0.1, 0.5, 1.0, 2.0, 4.0 and 6.0mol%, 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 (τ R ) and branching ratios for the fluorescent 4 G 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 4 G 5/2 → 6 H 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 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.