Abstract
Tellurite glasses (TeO2-ZnO-Nb2O5) mono-doped Er3+ and co-doped Er3+/Ce3+ have been prepared using the melt-quenching technique. To evaluate the effect of Ce3+ on the structural, thermal stability of glass hosts and fluorescence properties of Er3+, X-ray diffraction patterns, Ftir spectra, differential scanning calorimeter curves, absorption spectra, fluorescence emission spectra, fluorescence lifetimes, up-conversion emission spectra of glass samples were measured and investigated. Using Judd-Ofelt theory, we calculated intensity parameters (Omega(2), Omega(4) and Omega(6)), spontaneous emission probabilities, the radiative lifetime, luminescence branching factors and the quantum yield of luminescence for I-4(13/2) -> I-4(15/2) transition. The co-doping with Ce3+ was effective on the suppression of up-conversion emission of Er3+ owing to the phonon-assisted energy transfer: Er3+:I-4(11/2) + Ce3+:(2) F-5/2 -> Er3+:I-4(13/2) + Ce-3+:F-2(7/2) which contributed the effective enhancement of 1.53 mu m fluorescence emission. The change in optical properties with the addition of Ce3+ ions have been discussed and compared with other glasses. Using the Mc Cumber method for the I-4(13/2) -> I-4(15/2) transition, absorption cross-section, calculated emission cross-section, and gain cross-section values support that TZNEr1Ce1 glass is a potential material for developing broad-band and high-gain erbium-doped fiber amplifiers applied for 1.53 mu m.