Concentration dependence of visible luminescence from Pr3+-doped phosphate glasses

(a) Fluorescence spectra of 0.1 mol% and 3.0 mol% Pr3+-doped phosphate excited at 467 nm; (b) decay curves of 1D2 for 0.1 mol% and 3.0 mol% Pr3+-doped phosphate; (c) concentration dependence of fluorescence lifetime and corresponding the fitting curve; (d) energy diagram and cross relaxation process between Pr3+ ions.201