Energy transfer and population inversion in heavy metal oxide glasses doped with Tm3+ and Tb3+

Abstract

Emission properties and energy transfer of PbO-Bi2O3 Ga2O3-GeO2 glasses codoped with Tm3+ and Tb3+ ions were investigated. The 1.48-mum emission due to the Tm3+:H-3(4)-->F-3(4) transition can be used to amplify the S-band (1460-1530-nm) signal light. With Tb3+ addition, the lifetime and emission intensity of the Tm3+:F-3(4) level decreased sharply via the Tm3+:F-3(4)-->Tb3+:(7)Fn(0,1,2) energy transfer. Population densities of the F-3(4) and H-3(4) levels in Tm3+ calculated from rate equations clearly verified that population inversion in Tm3+ ions became possible with as little as 0.1 mol % of Tb3+ addition.