Monophase domain, fibers single crystals grown by the micro-pulling down technique and optical characterisation of LiGd1−xYbx(WO4)2

We have determined the single phase domain of LiGd1−xYbx(WO4)2. The lattices parameters decrease as a function of Yb3+ substitution in Gd3+ sites. Transparent LiGd1−xYbx(WO4)2 fibers single crystals were successfully grown by the micro-pulling down technique (μ-PD). The Yb3+-doped LiGd(WO4)2 fibers single crystals have been pulled under stationary stable growth conditions corresponding to flat crystallization interface with meniscus length equal to 120 μm. The fibers diameters varied from 0.5 to 1 mm depending on the capillary die diameter, pulling rate and the molten zone temperature. Fibers single crystals free of defects are observed for Ytterbium concentration in the melt up to 5 at%. Above this limit, inclusions and cracks appear and the optical quality of the fibers were deteriorated. The emission spectra of Yb3+-doped LiGd(WO4)2 were investigated.

► Many applications of sapphire today demand the highest quality. ► Growth of transparent and homogeneous sapphire shaped crystals has been performed. ► The grown crystals show high chemical homogeneities and good optical properties.