title: Photonic metamaterials by direct laser writing and silver chemical vapour deposition.
abstract: Metamaterials are artificial materials that--unlike natural substances--enable magnetism to be achieved at optical frequencies. The vast majority of photonic metamaterials has been fabricated by electron-beam lithography and evaporation of metal films, both of which are well-established two-dimensional (2D) technologies. Although stacking of three or four functional layers made using these methods has been reported, a truly 3D fabrication approach would be preferable for 3D photonic metamaterials. Here, we report first steps in this direction by using a combination of direct laser writing and silver chemical vapour deposition--the 3D analogues of electron-beam lithography and evaporation, respectively. The optical characterization of a planar test structure composed of elongated split-ring resonators is in good agreement with theory. Retrieval of the effective optical parameters reveals the importance of bi-anisotropy. Once suitable theoretical blueprints are available, our fabrication approach will enable rapid prototyping of truly 3D photonic metamaterials.
authors.affiliation: Institut für Angewandte Physik, Universität Karlsruhe (TH), D-76131 Karlsruhe, Germany.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Rill
authors.forename: Christine
authors.initials: C
authors.lastname: Plet
authors.forename: Michael
authors.initials: M
authors.lastname: Thiel
authors.forename: Isabelle
authors.initials: I
authors.lastname: Staude
authors.forename: Georg
authors.initials: G
authors.lastname: von Freymann
authors.forename: Stefan
authors.initials: S
authors.lastname: Linden
authors.forename: Martin
authors.initials: M
authors.lastname: Wegener