Spectral and luminescent properties of Bi-doped bulk glasses and factors acting on them

The properties near infrared (NIR) - emitting centers were investigated in Bi-doped Mg.Al-silicate and phosphate glasses. The NIR-emitting optical centers containing a pair of bismuth ions were shown to be formed in a reversible redox chemical reaction. The common electric charge (+5) of bismuth ions in such centers was determined. The NIR-emission saturation measurements have made it possible to calculate the ground-state absorption cross-section (~4.4×~10 -19 cm 2 ) of these centers at 532 nm and their absolute concentration in the glass. It was found that similar emitting centers can also be formed in a colorless and non-luminescent Bi-doped glass by γ-irradiation. This fact allowed deriving some conclusions on an optical center structure.