Improvement of 1.53 μm emission and energy transfer of Yb3+/Er3+ co-doped tellurite glass and fiber

To improve the 1.53 mu m band emission of Er3+, the trivalent Yb3+ ions were introduced into the Er3+ single-doped tellurite glass with composition of TeO2-ZnO-La2O3, a potential gain medium for Er3+-doped fiber amplifier (EDFA). The improved effects were investigated from the measured 1.53 mu m band and visible band spontaneous emission spectra together with the calculated 1.53 mu m band stimulated emission (signal gain) spectra under the excitation of 975 nm laser diode (LD). It was found that Yb3+/Er3+ co-doping scheme can remarkably improve the visible band up-conversion and the 1.53 mu m band fluorescence emission intensity, and meanwhile improves the 1.53 mu m band signal gain to some extent, which were attributed to the result of the effective energy transfer of Yb3+: F-2(5/2) + Er3+: I-4(15/2) -> Yb3+: F-2(7/2) + Er3+: I-4(11/2). The quantitative study of energy transfer mechanism was performed and microscopic energy transfer parameters between the doped rare-earth ions were determined. In addition, the spectroscopic properties of Er3+ were also investigated from the measured absorption spectrum according to the Judd-Ofelt theory, and the structure behavior and thermal stability of the prepared tellurite glass were analyzed based on the X-ray diffraction (XRD) and differential scanning calorimeter (DSC) measurements, respectively. (C) 2013 Elsevier Inc. All rights reserved.