The effect of P2O5 on the ultra broadband near-infrared luminescence from bismuth-doped SiO2–Al2O3–CaO glass

The effect of P2O5 on infrared luminescence properties of bismuth-doped SiO2–Al2O3–CaO (SAC) glass was investigated. Under excitation of 690 and 808 nm LD, two infrared emissions from bismuth ions central at 1100 and 1300 nm were observed, respectively. The addition of P2O5 was not only found to lead to the increase of full width at half maximum (FWHM) of two infrared emissions, but also result in intensity variety of the infrared emissions. The intensity of the infrared emission located at 1300 nm is reduced by a factor of 2, while the luminescence at 1110 nm is increased by a factor of 5. We propose that the infrared emissions at 1100 and 1300 nm may originate from different valence Bi ion in glasses. Compared with emission at 1300 nm, the infrared emissions at 1100 nm is more possibly from the transition of lower valent Bi ion.