Nd3+→Yb3+ resonant energy transfer in the ferroelectric Sr0.6Ba0.4Nb2O6 laser crystal

Resonant (nonphonon-assisted) Nd(3+)-> Yb(3+) energy transfer has been observed in Nd(3+) and Yb(3+) codoped Sr(0.6)Ba(0.4)(NbO(3))(2) crystals. The Nd(3+)-> Yb(3+) energy transfer in this system has been compared to those taking place in other Nd(3+)-Yb(3+) codoped hosts, for which, in most of cases, the transfer is only possible by assistance of phonons. The resonant nature is explained as a result of both the very broad optical bands of Nd(3+) and Yb(3+) ions in Sr(0.6)Ba(0.4)(NbO(3))(2) and the short energy gap (636 cm(-1)) between the (4)F(3/2) (Nd(3+)) and (2)F(5/2) (Yb(3+)) excited states. Spectroscopic data revealed that the energy transfer occurs via a nonradiative process and is dominated by an electric dipole-dipole interaction. The most relevant spectroscopic properties of the Nd(3+)-> Yb(3+) energy transfer have been systematically investigated as a function of Yb(3+) ion concentration. The energy transfer efficiency increases linearly with the Yb(3+) ion concentration so that about a 50% is attained for a 10 at. % of ion acceptor concentration.