A promising nonlinear optical material in the Mid-IR region: new results on synthesis, crystal structure and properties of noncentrosymmetric β-HgBrCl

Abstract

This paper reports, for the first time, the nonlinear optical property of β-HgBrCl, which was synthesized by a reaction of Hg₂Cl₂ and Br₂ in EtOH. This reaction also gave α-HgBrCl. And the single crystal structures of both α- and β-HgBrCl are presented and compared. β-HgBrCl shows phase-matchable powder second harmonic generation (SHG) effect of about 2 times that of KH₂PO₄ (KDP). Its absorption edge in UV-vis spectrum locates at 366 nm, implying a wide band gap and therefore higher laser damage threshold. It also exhibits a relatively wide transparent window (from 0.4 to 20 μm) and relatively good thermal stability.