Broad-band 1.5 μm emission of Er3+ ions in bismuth-based oxide glasses for potential WDM amplifier

Erbium-doped glasses showing the widest 1.5 mu m emission band are reported in a novel oxide system Bi2O3-B2O3-SiO2 and their optical properties such as absorption, emission spectra, cross sections, the Judd-Ofelt parameters and fluorescence lifetime were investigated. The broad and flat I-4(1 3/2) - I-4(1 5/2) emission of Er3+ ions around 1.5-1.6 mu m can be used as an excellent optical amplifier for the wavelength-division-multiplexing (WDM) network system. Among three Judd-Ofelt intensity parameters of Er3+ ions, the Omega(6) showed very large value in these glasses compared with other oxide and fluoride glasses ever reported. The cross section of the 1.5 mu m transition was quite large due to a large refractive index of the host. With increasing B2O3 content in the glass composition, the bandwidth increased, while the lifetime of the I-4(1 3/2) level decreased. A strong correlation was found between the bandwidth, spontaneous emission probability and the value of the Omega(6) parameter. These optical characteristics were discussed combined with local environment of Er2+ ions in these novel glasses. (C) 2000 Elsevier Science B.V. All rights reserved.