Anisotropy of second-order nonlinear optical susceptibilities of arsenic triiodide-sulfur addition complex: ASI(3) center dot 3S(8)

作者：Kelly J F; Samoc A^*; Samoc M; Krausz E R; Willis A C

来源：Optics Communications, 2006, 264(1): 35-44.

DOI：10.1016/j.optcom.2006.02.049

• quadratic nonlinear optical susceptibility
• first hyperpolarizability
• arsenic triiodide-sulfur adduct
• molecular crystal
• second harmonic generation

We report the anisotropic linear and second-order nonlinear optical (NLO) properties of arsenic triiodide-octa-sulfur (1:3) adduct, AsI3 center dot 3S(8), which spontaneously crystallizes in the trigonal rhombohedral non-centrosymmetric space group R3m. The trigonal symmetry of the AsI3 center dot 3S(8) molecule coincides with the crystal symmetry. The crystals are optically uniaxial with n(o)/n(e) of about 1.2 and show dichroism at the UV-visible wavelengths. Second harmonic generation (SHG) tensor elements were determined from Maker fringes measured with an Nd:YAG laser (similar to 10 ns pulse, 1064 nm). The coefficient d(222,eff) = 32.0 pm/V for the light polarized parallel to the layers of iodine and sulfur atoms in the AsI3 center dot 3S(8) crystal ab plane is markedly larger than d333 = 11.6 pm/V for the polarization of light parallel to the crystal c axis. The anisotropy parameter, defined as the d(222,eff)/d(333) ratio, is about 2.7 for the AsI3 - 3S(8) crystal, smaller than that for the isomorphous CHI3 center dot 3S(8) crystal (7.3) but larger than for the SbI3 center dot 3S(8) crystal (0.7). Highly anisotropic components of the first hyperpolarizability tensor of an AsI3 center dot 3S(8) molecule, fl, were derived from the quadratic nonlinear susceptibility tensor of the crystal.

• 出版日期2006-8-1