Near-infrared and mid-infrared (MIR) ultrabroad emission bands were observed in as-grown and annealed Bi(2)O(3)-GeO(2) binary glasses, in the wavelength ranges of 1000-1800 nm and 1800-3020 nm, respectively. The MIR emission band could appear through high doping ratio of Bi(2)O(3) or annealing process in air atmosphere. The structure of these glasses, the transformation of emission centers, and the effect of Al ions doping have been discussed, with the conclusion that the Bi(2)O(3)-GeO(2) binary glasses could be a promising laser material.
