Growth and theoretical study on the deep-ultraviolet transparent β-CsBa2(PO3)5 nonlinear optical crystal

Abstract

We have successfully grown β-CsBa₂(PO₃)₅ (β-CBPO) crystals by a high-temperature solution method. The optical transmittance spectrum shows that the crystal exhibits high transparency in the deep-ultraviolet region. According to the first-principles calculations, the optical properties of β-CBPO are mainly determined by the P–O covalent bonds. In addition, the β-CBPO crystals have larger nonlinear optical activity; the maximum second-harmonic generation coefficient calculated for β-CBPO is 0.45 pm V⁻¹, which is larger than that of KDP (0.39 pm V⁻¹).