A New Promising Nonlinear Optical (NLO) Crystal For Visible And Ultraviolet (UV) Regions

Different La1-xGdxSc3(BO3)(4) compounds with 0 <= x <= 0.5 were synthesized by solid-state reaction method. The X-ray diffraction studies revealed that the compounds containing more than 30 at.% Gd3+ ions have non-centrosymmetric trigonal structure (space group R32) and, consequently they are optically nonlinear. A crystal of LaxGdyScz(BO3)(4) (x + y + z = 4) - LGSB with La0.75Gd0.5Sc2.75(BO3)(4) starting melt composition and relatively small dimensions (about 10 mm in diameter and 25 mm in length) was grown by the Czochralski method. In order to confirm the NLO property, the as-grown crystal was subjected to second-harmonic generation (SHG) test. The nonlinear coefficient d(11) of LGSB crystal has been preliminary estimated to be about 1.9 pm/V, which is larger than that of YAl3(BO3)(4) (YAB) crystal.