title: Gold helix photonic metamaterials: a numerical parameter study.
abstract: We have recently shown that metamaterials composed of three-dimensional gold helices periodically arranged on a square lattice can be used as compact "thin-film" circular polarizers with one octave bandwidth. The physics of the motif of these artificial crystals is closely related to that of microwave sub-wavelength helical antennas in end-fire geometry. Here, we systematically study the dependence of the metamaterial's chiral optical properties on helix pitch, helix radius, two-dimensional lattice constant, wire radius, number of helix pitches, and angle of incidence. Our numerical calculations show that the optical properties are governed by resonances of the individual helices, yet modified by interaction effects. Furthermore, our study shows possibilities and limitations regarding performance optimization.
authors.affiliation: Institut für Angewandte Physik and DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
authors.forename: Justyna K
authors.initials: JK
authors.lastname: Gansel
authors.forename: Martin
authors.initials: M
authors.lastname: Wegener
authors.forename: Sven
authors.initials: S
authors.lastname: Burger
authors.forename: Stefan
authors.initials: S
authors.lastname: Linden
mesh_terms: D003198:Computer Simulation; D006046:Gold / Q000737:chemistry*; D008027:Light; D008420:Manufactured Materials; D008956:Models, Chemical; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation
chemical_list: D006046:Gold