Laser site selective excitation of KY3F10-doped with samarium

Laser selective excitation has identified three Sm2+ centres in KY3F10 Of these, two exhibit strong up-conversion fluorescence due to sequential absorption from the metastable D-5(0) multiplet and high lying 4f(5)5d states. The observation of Sm2+ in KY3F10 appears to provide further evidence for the presence of F- vacancies as proposed by previous workers. The expected Sm3+ C-4v symmetry centre is also observed. A crystal-held analysis of the 46 measured electronic energy levels of this centre, yields parameters consistent with those of other trivalent rare-earth ions in this material. (C) 1999 Elsevier Science B.V. All rights reserved.