Infrared energy transfer in Tm3+:LiNbO3

The infrared optical properties of LiNbO3 crystals doped with variable thulium concentrations have been studied. In particular, the infrared emissions that appear after direct pumping to the 3H4 multiplet (795 nm) have been analyzed. The emission spectra, as well as the lifetimes, show that an efficient energy transfer between 3F4 and 3H4 levels takes place. The concentration dependence of the lifetimes has been studied and the transfer probability has been characterized.