“…The resolution of the spectral features obtained here allow for the first time a clear identification of the excited levels of Sm 2+ in YPO 4 host. These excitation peaks arise from internal 4f-4f transitions of Sm 2+ and, in combination with the previous work regarding analysing the emission lines (Poolton et al, 2012), we tentatively assign 7 F 0 → 5 D 0,1,2,3 at 1.837, 1.879, 1.898 and 1.977 eV respectively, and 7 F 1 → 5 D 0 at 1.785 eV. Low intensity phonon replicas (~20 meV) associated with each electronic transition are also observed.…”