The near-infrared broadband emission from bismuth-doped GeO2–WO3 and GeO2–BaO glasses

Glasses with the composition of (99.5 – χ)GeO2–χWO3–0.5Bi2O3 (χ = 3, 6, 9 mol%) and (99.5 – ψ)GeO2–ψBaO–0.5Bi2O3 (ψ = 3, 6, 9 mol%) were prepared. Their thermal, emission and absorption measurements were carried out. The near-infrared super broadband emission of the prepared samples peak around 1.3 μm was discovered. The results indicated, in GeO2–WO3–Bi2O3 glasses, increasing amount of WO3 brought about the broadening of FWHM, prolonging of lifetime and enhancing of thermal stabilities. While in GeO2–BaO–Bi2O3 glasses, concomitant with the increasing amount of BaO were the broadened FWHM as well as the prolonged lifetime. Red-shift tendency of absorption edges was discovered in both two groups of glasses indicating the Bi5+ ions might take responsibility for the broadband emission.