GdxLa1−xSc3(BO3)4: A new nonlinear optical crystal

A new nonlinear optical material GdxLa1−xSc3(BO3)4 (GLSB) has been synthesized in the trigonal huntite-type structure. The composition parameter x, which defines the existence region of the trigonal huntite-type structure, was determined. Large single crystals were successfully grown by a high-temperature top-seeded solution growth method using Li6B4O9–LiF as a flux. Evidenced by single-crystal X-ray diffraction measurements, the member Gd0.22La0.78Sc3(BO3)4 crystallized in space group R32 with cell dimensions a=9.7933 and c=7.9540 Å. The UV absorption edge for polished pieces exhibited at a wavelength shorter than 200 nm. Sellmeier equations were established on the basis of the refractive indices measured by the auto-collimation method. The nonlinear optical coefficient d11 was determined to be 2.08 pm/V by the modeling and optical measurements of powders.

► Nonlinear optical material GdxLa1−xSc3(BO3)4 crystallizing in trigonal huntite structure has been obtained by an approach of size tuning on rare-earth ions.
► The transparency range of the crystal spans a wide field and the short-wavelength transmission cut-off extends to the deep UV.
► The crystal is phase matchable in the UV region with respect to second harmonic generation.
► The nonlinear optical coefficient is 2.08 pm/V, more than five times of d36 of KDP.