Ultrabroadband near-infrared emission from a colorless bismuth-doped glass

The characteristics of bismuth-doped glasses were investigated as colorless ultrabroadband near-infrared gain media. The colorless Bi-doped soda-lime-silicate glass was prepared under controlled redox conditions, and it realized the broadest near-infrared emission of about $600\mathrm{nm}$ in full width at half maximum, centered at $1000\mathrm{nm}$ , under $720\mathrm{nm}$ excitation. The emission band extended toward shorter wavelengths compared with the shortest wavelength for the Bi-doped glass ever reported. The colorless Bi-doped glass developed in this work has a good potential for the broadband gain media for amplifiers and tunable lasers.