An Effective Strategy for Designing Nonlinear Optical Crystals by Combining the Structure-Directing Property of Oxyfluorides with Chemical Substitution

摘要

Rationally designing a high-performance nonlinear optical (NLO) crystal remains a great ongoing challenge. It involves not only the design of noncentrosymmetric structures but also property optimization. In this communication, a new strategy for effectively designing the NLO crystal has been put forward, that is, using the structure-directing property of oxyfluoride anions to obtain a noncentrosymmetric and polar structure, and then by substitution of IO3- for isovalent F- anions to further enhance the SHG response. With this strategy, a new iodate fluoride, Ba-2[MoO3F(IO3)](MoO3F2) has been successfully designed from the Ba-2(MoO3F2)F-2 with the cis-directing [MoO4F2](4-) groups. It exhibits a large SHG response (approximate to 8xKDP), a wide transparent region (0.30-10.92 mu m), a high laser-induced damage threshold (LDT) (88.53 MW cm(-2)), and a large birefringence (approximate to 0.264@532 nm). These indicate Ba-2[MoO3F(IO3)](MoO3F2) would be a promising NLO crystal.