Recent advances of inorganic phosphates with UV/DUV cutoff edge and large second harmonic response

Phosphates are important candidates for ultraviolet/deep-ultraviolet (UV/DUV) nonlinear optical (NLO) materials by good transparency ability and variability of anion species as well as different coordinated cations. Phosphates have been reported as minerals or NLO materials with abundant condensed anionic framework. For phosphate-based NLO materials, how to improve the second harmonic generation (SHG) response and birefringence remains a great challenge. Herein, this review analyzes the structure-property relationship of the representative UV/DUV phosphates, and the microscopic mechanism to achieve a balance between the short absorption edge and large SHG response is summarized. It provides a new idea to study the UV/DUV phosphate NLO materials.