Structural study of the origin of the largest 1.5 μm Er3+ luminescence band width in multicomponent silicate glass

We report the 1.5 mu m emission band broadening of Er3+ observed in multicomponent SiO2-GeO2-B2O3-Na2O glasses. The largest bandwidth Delta lambda(eff) = 95.6 nm was obtained in glass with a composition of 66.75% SiO2-13% GeO2-6% B2O3-4.45% Na2O in wt.%. The band broadening was found to be dealt with: 1) high Er3+ concentration broadening; 2) Yb3+ co-doped broadening; 3) B2O3 broadening; and 4) the reduction of Na2O content broadening. FT-IR spectra showed that the network structure of glasses changed with the glass compositions, which was proven by the significant change of the vibration band of Si - O at 1100 cm(-1) in the shape and intensity. It resulted in a significant change of the local environment of Er3+ ions and evidenced the variation of bond covalence between Er ions and local ligands. The high Judd-Ofelt parameters influenced the broad band emission for these low refractive index (1.50-1.54) glasses. (C) 2014 Elsevier B.V. All rights reserved.