title: Polarization-controlled circular second-harmonic generation from metal hole arrays with threefold rotational symmetry.
abstract: The discrete rotational symmetry of nanostructures provides a powerful and simple guiding principle for designing the second-harmonic generation process in nonlinear metamaterials. We demonstrate that, in achiral nanostructures with threefold rotational symmetries, a circularly polarized fundamental beam produces a countercircularly polarized second-harmonic beam. In this case, the polarization state of the second harmonic is determined in a very simple manner. We also demonstrate how rotational symmetries in nonlinear metamaterials manifest themselves in SHG selection rules.
authors.affiliation: Photon Science Center, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Konishi
authors.affiliation: Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Photon Science Center, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Jakob
authors.initials: J
authors.lastname: Larsson
authors.affiliation: Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Ishii
authors.affiliation: Photon Science Center, The University of Tokyo, Tokyo 113-8656, Japan and Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuwata-Gonokami