A novel deep UV nonlinear optical crystal Ba3B6O11F2, with a new fundamental building block, B6O14 group

Abstract

Single crystals of Ba₃B₆O₁₁F₂ have been synthesized by introducing the F⁻ anion into the BaO-B₂O₃ system and the structure was determined by single-crystal X-ray diffraction. It crystallizes in the non-centrosymmetric space group P2₁ (no. 4). In the structure, a new fundamental building block, the B₆O₁₄ group, was observed. The second harmonic generation (SHG) measurement shows that Ba₃B₆O₁₁F₂ possesses a large SHG response about three times that of KH₂PO₄ (KDP) and is phase-matchable. In addition, it exhibits a wide transparency range with a short UV cut-off edge (<190 nm), which suggests that the material is a potential deep UV nonlinear optical material.