Erbium-doped tellurite-based glasses(Er3+:TeO2-ZnO-La2O3) are prepared by the conventional melt-quenching technique,and concentration-dependent luminescence properties of Er3+ are investigated.A significant spectral broadening of the 1.53 μm fluorescence corresponding to 4I13/2 →4I15/2 transition is observed,and the fluorescence decaying becomes a nearly exponential way with the increasing Er3+concentration.Radiation trapping is evoked to explain the broadening of 4I13/2 → 4I15/2 emission line of Er3+ ions.The optimum doping content of Er2O3 for 1.53 μm fluorescence emission is about 1.5 mol%.
The high phonon energy oxide of B2O3 is introduced into the Er3+/Ce3+co-doped tellurite-niobium glasses with composition of TeO2-Nb2O5-ZnO-Na2O.The absorption spectra,1.53 μm band fluorescence spectra,fluorescence lifetime and Raman spectra of Er3+in glass samples are measured together with the calculations of Judd-Ofelt spectroscopic parameter,stimulated emission and absorption cross-sections,which evaluate the effect of B2O3 on the 1.53 μm band spectroscopic properties of Er3+.It is shown that the introduction of an appropriate amount of B2O3 can further improve the 1.53 μm band fluorescence intensity through an enhanced phonon-assisted energy transfer(ET) between Er3+/Ce3+ions.The results indicate that the prepared Er3+/Ce3+co-doped tellurite-niobium glass with an appropriate amount of B2O3 is a potential gain medium for the 1.53 μm bandbroad erbium-doped fiber amplifier(EDFA).
