Growth and spectroscopic studies of NaLa(MoO4)2:Tm3+ crystals: A new promising laser material

Single crystals of scheelite-like disordered double molybdate NaLa(MoO4)2 doped with thulium ions with dopant concentrations of 3.0 × 1019 and 1.2 × 1020 cm−3 are grown by the Czochralski method. Spectral and luminescent studies of crystals grown are performed in wavelength ranges of 800 nm (the transitions 3 H 6↔3 H 4) and 2 μm (the transitions 3 H 6↔3 F 4), including the measurements of the polarized absorption and luminescence spectra of these crystals and the decay kinetics of their excited states. A model that satisfactorily describes the decay kinetics of the luminescence from the 3 H 4 level taking into account cross-relaxation interactions is proposed. The prospects for the use of these crystals as active media in two-micrometer solid-state lasers are discussed.