Effect of Ce 3+(Eu 3+) codoping on the spectroscopic properties of Er 3+ in bismuth-germanate glass

Abstract

In order to improve the transition rate from the 4I 11/2 level to the 1.53 μm fluorescence emitting 4I 13/2 level of Er 3+, the Ce 3+ and Eu 3+ ions were respectively introduced into the Er 3+ doped bismuth-germanate glass with a composition of Bi 2O 3–GeO 2–Ga 2O 3–Na 2O. The energy transfer mechanisms between Er 3+ and the codopants were discussed based on their energy level diagrams. Though Ce 3+ was less effective than Eu 3+ on the decrease of the 4I 11/2 level lifetime, it hardly influenced the lifetime value of 4I 13/2 level. Both the 4I 11/2 and 4I 13/2 levels were depleted severely at the same time with the codoping of Eu 3+. As a result, Er 3+/Ce 3+ codoping improved the 1.53 μm fluorescence emission intensity, while Er 3+/Eu 3+ codoping had a deleterious effect on it. The results indicate that the Er 3+/Ce 3+ is a preferable codoped scheme for bismuth-germanate glass with low phonon energy to obtain an efficient broadband EDFA pumped at 980 nm.