Symmetry and phase determination of second-harmonic reflection from calcite surfaces

Summary form only given. Measurements of the azimuthal anisotropy of second-harmonic reflection (SHR) has proved to be a sensitive tool to determine the symmetry of any surface. Here we study surfaces of a noncubic material: we perform SHR on calcite, which is a rhombohedric crystal. An important issue is to determine the phase of the various tensorial components of the effective nonlinear susceptibility. The interference techniques are very powerful, but not so easy to use, given the usually weak signal measured in the experiments. We use another technique which has been developed recently and consists in recording the SHR signal as a function of the ellipticity of the fundamental beam polarization. It allows to get relative magnitudes and phases of the nonlinear tensor components.