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 LiGd 1− x Yb x (WO 4 ) 2 . The lattices parameters decrease as a function of Yb 3+ substitution in Gd 3+ sites. Transparent LiGd 1− x Yb x (WO 4 ) 2 fibers single crystals were successfully grown by the micro-pulling down technique (μ-PD). The Yb 3+ -doped LiGd(WO 4 ) 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 Yb 3+ -doped LiGd(WO 4 ) 2 were investigated.