Spectroscopy and energy transfer parameters of Tm3+- and Ho3+-doped Ba2NaNb5O15 single crystals

The absorption and emission spectra of Tm3+- and Ho3+-doped Ba2NaNb5O15 crystals have been measured in the 1.5-2 mu m region. The lifetimes of the lowest excited states have been measured at 10 and at 298 K. The cross sections of the (Tm) F-3(4) <-> H-3(6) and (Ho) I-5(7) <-> I-5(8) transitions have been estimated and used to determine the (Tm) F-3(4) -> (Ho) I-5(7) energy transfer parameter. These results are discussed in order to evaluate the potentialities of this material as active medium in solid-state lasers operating at 2 Pm. (c) 2006 Elsevier B.V. All rights reserved.