Growth and spectroscopic investigations of new crystal Er(3+),Ce(3+) : NaLa(MoO(4))(2) promising for 1.5 mu m solid-state lasers

Scheelite-like disordered double sodium-lanthanum molybdate NaLa(MoO(4))(2) single crystals co-doped with Er(3+) and different concentrations of Ce(3+) have been grown by Czochralski technique. The 300K spectroscopic properties of the excited states (4)S(3/2), (4)I(11/2) and (4)I(13/2) of Er(3+) ions in grown crystals as a function of Cerium concentration have been investigated. The lifetime of (4)I(11/2) have been found to reduce from 130 mu s in the solely Er-doped sample to approximately 3.5 mu s, when the concentration of Ce reaches 50 at. %. At the same time the lifetime of (4)I(13/2) level at 300 K remains unchanged (3.7 ms) up to the concentration of Ce in crystal equal to 10 at. %, and reduces by less than 30% (2.6 ms) in the 50 at. % Ce co-doped sample. This result looks very promising from point of view of obtaining low-threshold 1.5 mu m laser oscillation.