Spectroscopic properties of Er 3+: 4I 13/2 level in Bi 2O 3–B 2O 3–GeO 2–Na 2O glasses

Abstract

Spectroscopic properties of Er 3+: 4I 13/2 → 4I 15/2 transitions in erbium-doped bismuth-borate glasses with composition of 45Bi 2O 3–35B 2O 3–10GeO 2–10Na 2O were investigated. The results show that the fluorescence intensity reveals a nonexponential decaying behavior for glasses with low Er 3+-doped concentration. It is ascribed to the energy transfer from Er 3+ to OH − groups, and the energy-transfer microparameter C Er–OH is about 33.1 × 10 −40 cm 6 s −1 in Er 2O 3-doped content of 0.1 mol% glass. Whereas an exponential behavior is dominant for glasses with high Er 3+-doped case. Nonradiative decay in the latter is mainly originated from the energy migration among Er 3+ ions, and this energy migration is also responsible for the concentration quenching of 1.53 μm fluorescence emission. The interaction microparameter C Er–Er for the migration among Er 3+ ions was calculated to be an average of 43.9 × 10 −40 cm 6 s −1. Meanwhile, the radiation trapping of Er 3+ leads to the effective emission width broadening from 66.3 to 82.5 nm with Er 2O 3 doped content increased from 0.1 to 3.0 mol%.