The 1.53 μm spectroscopic properties and thermal stability in Er3+/Ce3+ codoped TeO2–WO3–Na2O–Nb2O5 glasses

Abstract

Er3+/Ce3+ codoped tellurite-based glasses with composition of TeO2–WO3–Na2O–Nb2O5 were prepared by high-temperature melt-quenching technique and a detailed study of the 1.53μm band spectroscopic properties and thermal stability was presented in this paper. The absorption spectra, visible upconversion spectra, 1.53μm band fluorescence spectra, fluorescence lifetimes, Raman spectra, differential scanning calorimeter (DSC) and X-ray diffraction (XRD) curves of glass samples were measured and investigated, together with the quantitative calculations and analyses of Judd–Ofelt intensity parameters, stimulated emission and absorption cross-sections, amplification quality factors, energy transfer rates and quantum transition efficiencies. It was found that the prepared glass samples have good thermal stability (Tg>425°C), large Judd–Ofelt intensity parameter (Ω6>0.80×10−20cm2) and bandwidth quality factor (σep×FWHM>360×10−21cm2nm) of Er3+. With the increasing of Ce3+ doped concentration, the visible upconversion emission decreased while the 1.53μm band fluorescence intensity improved significantly due to the enhanced energy transfer of Er3+:4I11/2+Ce3+:2F5/2→Er3+:4I13/2+Ce3+:2F7/2 owing to the moderate phonon energy (∼930cm−1) of glass host, which was beneficial in compensating for the existing energy mismatch between the Er3+:4I11/2→4I13/2 emission and Ce3+:2F5/2→2F7/2 absorption transitions. Compared with the Er3+ single-doped case, the 1.53μm band fluorescence intensity in Er3+/Ce3+ codoped glass sample could increase by about 30%. The results indicate that the prepared tellurite-based glass with a suitable Er3+/Ce3+ codoping concentration is an excellent gain medium applied for broadband EDFA pumped with a 980nm laser diode.