The SHG anisotropy pattern of a reconstructed gold(110) electrode

Second harmonic generation (SHG) anisotropy has been employed to study the rotational symmetries of single crystalline surfaces for many years. However, their symmetry contributions can only be evaluated for simple anisotropy patterns with sufficient accuracy. Such an analysis is generally not possible for reconstructed or microfaceted surfaces. We have, therefore, developed a novel approach, the interference SHG anisotropy (ISHGA). It permits an easy and reliable decomposition of the SH field into its isotropic and anisotropic components. The analysis of the ISHGA data provides new insights leading to a generalized model of anisotropic contributions, necessary to describe complex SHG anisotropy patterns like that of the Au(110) surface which reconstructs by building coexisting domains of 1×2 and 1×3 microfacets.