Synthesis, Characterization, and Crystal Growth of Cs₂Hg₃I₈: A New Second-Order Nonlinear Optical Material

This paper reports, for the first time, the second-order nonlinear optical (NLO) property of Cs2Hg3I8, a new potential NLO material in the infrared region. The compound exhibits a powder second harmonic generation (SHG) effect as strong as KTiOPO4 (KTP). It also shows excellent transparency in the range of 0.5−25 μm with relatively high thermal stability. A single crystal up to 25 × 14 × 5 mm3 in size has been grown in acetone by a slow evaporation technique.