Optical properties of and concentration quenching in Bi2O3-B2O3-Ga2O3 glasses

Er2O3-doped Bi2O3-B2O3-Ga2O3 glasses were prepared by the conventional melt-quenching method, and the Er3+:I-4(13/2) -> I-4(15/2) fluorescence properties are studied for different Er3+ concentrations. when the Er2O3 concentration increases from 0.03 to 3.0 mol%, the measured lifetime of Er3+:I-4(13/2) level decrease from 2.24 to 0.9 m s, and from 0.25 to 0.20 m s for the Er3+:I-4(11/2) level. The fast energy migration among Er3+ ions cause the reduction of lifetime of the I-4(13/2) level, whereas the change in the I-4(11/2) level is mainly due to a cooperative upconversion process (I-4(11/2),I-4(11/2)) -> (F-4(7/2),I-4(15/2)). Based on the dipole-dipole interaction theory, the interaction parameter, C-Er.Er, for the migration rate of Er3+ : I-4(13/2) <-> I-4(13/2) was calculated to be 32 x 10(-40) cm(6) S-1. (c) 2007 Published by Flsevier B.V.