Holmium doped barium gallo-germanate glasses for near-infrared luminescence at 2000 nm

Holmium singly doped barium gallo-germanate glasses have been studied for near-infrared luminescence at 2000 nm. Near-infrared luminescence spectra corresponding to I-5(7) -> I-5(8) transition of trivalent holmium and their decays have been examined as a function of BaF2 and activator (Ho3+) concentration. The integrated intensities of luminescence bands increase up to 0.5 mol% Ho3+ and then reduce with further increasing activator (Ho3+) concentration. Luminescence linewidths increase with increasing Ho3+ concentration, but remain nearly unchanged with BaF2 content. The glass samples exhibit the shortened decay curves with increasing activator concentration, which is due to the presence of energy transfer between Ho3+ ions. The luminescence lifetime I-5(7) (Ho3+) is found to be maximum at 5 mol% of BaF2.