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

This paper reports, for the first time, the nonlinear optical property of beta-HgBrCl, which was synthesized by a reaction of Hg2Cl2 and Br-2 in EtOH. This reaction also gave alpha-HgBrCl. And the single crystal structures of both alpha- and beta-HgBrCl are presented and compared. beta-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 mu m) and relatively good thermal stability.