Laser spectroscopic studies of Tb3+-doped oxyfluoroborate glass

Tb3+-doped oxyfluoroborate glasses have been prepared for different concent rations of Tb. The absorption, fluorescence and photoacoustic spectra of th ese have been recorded and studied. It is marked that the fluorescence inte nsity of different fluorescence transitions decreases with the increase of Tb ion concentration in the glass. This quenching at higher concentration i s due to the energy transfer among the excited and nearest neighbor unexcit ed Tb ions in the glass. The lifetime measurement confirms it, as the lifet ime of a particular state was found to decrease with the increase of Tb ion concentration in the glass. The mechanism of the energy transfer process w as determined to involve quadrupole-quadrupole interaction. We have also st udied the energy transfer from Tb3+ --> Pr3+ when both the rare earths are doped together in the glass. A decrease in the lifetime of the D-5(4) level of Tb3+ with the increase of Pr3+ concentration confirms this. (C) 2000 El sevier Science B.V. All rights reserved.