Effect of Ce3+ on the spectroscopic properties in Er3+ doped TeO2-GeO2-Nb2O5-Li2O glasses

The Ce3+ ion was introduced into Er3+ doped TeO2-GeO2-Nb2O5-Li2O (TGNL) glass to improve the 1.5 μm fluorescence characteristics. As increasing of Ce3+ concentration, the lifetime of Er3+:4I11/2 level is shortened form 360 to 225 μs, while the Er3+:4I13/2 level remains unchanged. Accordingly, the upconversion fluorescence (blue, green and red) was quenched. Improved 1.5 μm emission is obtained and the reason is ascribed to the increase of nonradiative rate between the 4I11/2 and 4I13/2 level of the Er3+ ions.