Photoluminescence of new fluorophosphate glasses containing a high concentration of terbium(III) ions

Novel fluorophosphate glasses containing a heavy concentration of Tb3+ ions are studied in terms of optical absorption and emission, and decaytimes. From the D-5(4) emitting level, an intense green luminescence is observed, The decay is single-exponential whatever the terbium concentration which can be as large as 36 mol%. At high concentrations, a fast diffusion process is responsible for the energy migration from that level. For 5D(3), on the other hand, emissions are strongly concentration-dependent, and the decays are well accounted for by the Inokuti-Hirayama model.