Infrared luminescence properties of bismuth-doped barium silicate glasses

Infrared (IR) luminescence covering 1.1 to ∼1.6 μm wavelength region was observed from bismuth-doped barium silicate glasses, excited by a laser diode at 808 nm wavelength region, at room temperature. The peak of the IR luminescence appears at 1325 nm. A full width half-maximum (FWHM) and the lifetime of the fluorescence is more than 200 nm and 400 μs, respectively. The fluorescence intensity increases with Al₂O₃ content, but decreases with BaO content. We suggest that the IR luminescence should be ascribed to the low valence state of bismuth Bi²⁺ or Bi⁺, and Al³⁺ ions play an indirect dispersing role for the infrared luminescent centers.