A promising new nonlinear optical crystal with high laser damage threshold for application in the IR region: synthesis, crystal structure and properties of noncentrosymmetric CsHgBr3

Abstract

Searching for new IR nonlinear optical (NLO) crystals with high laser damage threshold (LDT) has become one of the great challenges in this field. This paper reports the synthesis, single crystal structure and properties of noncentrosymmetric CsHgBr₃, which is a new crystalline phase and shows a high LDT of about 226 MW cm⁻², together with good comprehensive performance. Its crystal can be obtained by reaction of CsBr and HgCl₂ in acetone. It crystallizes in the trigonal space group P3₂ (no. 145). Its powders show a phase-matchable second harmonic generation as strong as that of KH₂PO₄ (KDP). It also displays excellent transparency in the range of 0.42–31 μm and is thermally stable up to 250 °C. All these behaviors make it a promising new NLO crystal in the mid-IR region.