Results
3.1. Absorption and energy level analysis
The optical absorption spectra of PKSASm10 and PKFSASm10 glasses measured in UV–visible-NIR regions are shown in Fig. 1. The partial energy level diagram and cross-relaxation channels of Sm3 +-ions in phosphate glass are shown in Fig. 2. The observed band positions along with their assignments are presented in Table 2 and are comparable with some of the reported systems: PKBAS10:58.5 P2O5 + 17 K2O + 14.5 BaO + 9 Al2O3 + 1.0 Sm2O3[24]; PKBFAS10: 55.5 P2O5 + 17 K2O + 11.5 BaO + 6 BaF2 + 9 Al2O3 + 1.0 Sm2O3[24]; L5BS10: 49.5 Li2CO3 + 49.5 H3BO3 + 1.0 Sm2O3[32]; L5FBS10: 49.5 LiF + 49.5 H3BO3 + 1.0 Sm2O3[32] and Sm3 +:aquo-ion [30].