Gold Helix Photonic Metamaterial as Broadband Circular Polarizer

Abstract

We investigated propagation of light through a uniaxial photonic metamaterial composed of three-dimensional gold helices arranged on a two-dimensional square lattice. These nanostructures are fabricated via an approach based on direct laser writing into a positive-tone photoresist followed by electrochemical deposition of gold. For propagation of light along the helix axis, the structure blocks the circular polarization with the same handedness as the helices, whereas it transmits the other, for a frequency range exceeding one octave. The structure is scalable to other frequency ranges and can be used as a compact broadband circular polarizer.

Metamaterials: a new frontier of science and technology

“…[58][59][60] Very recently, light propagation through three-dimensional gold helices has been investigated in the mid-infrared region. 61 The structure can block the circular polarization with the same handedness as the helices, while it transmits the other with very high efficiency over a broad wavelength band (Fig. 6(f)).…”

Twisted optical metamaterials for planarized ultrathin broadband circular polarizers

“…On the basis of these concepts, three-dimensional (3D) chiral structures such as helices may be used to realize circular polarizers 1,2 . Similarly, cholesteric liquid crystals are composed of chiral molecules with a helical pitch that may be used to selectively filter one circular polarization based on Bragg reflection [3][4][5][6] .…”

“…An exciting possibility in this context is provided by direct laser writing 22,23 , which ensures large flexibility in the shape of the realizable 3D metamaterial inclusions. Broadband infrared circular polarizers based on gold helical metamaterials 1 have been recently demonstrated using this technique; however, realizing these structures in the visible is hindered by the minimum realizable features imposed by the diffraction limit.…”

Fabrication and Replication of Arrays of Single- or Multicomponent Nanostructures by Replica Molding and Mechanical Sectioning

“…The most sophisticated patterns are fabricated using electron-beam lithography (EBL), 17 focusedion beam (FIB) milling and lithography, 14 or direct laser writing. 18 These techniques can generate nearly arbitrary patterns in resists (e.g., EBL) or hard materials (e.g., FIB milling), but they are serial, expensive, and require access to a cleanroom.A number of techniques have emerged that have begun to address the challenges associated with conventional scanningbeam lithographic tools. 19 Xia and coworkers recently reviewed synthetic methods that can produce large quantities of high-quality metallic structures for plasmonic applications.…”

“…The most sophisticated patterns are fabricated using electron-beam lithography (EBL), 17 focusedion beam (FIB) milling and lithography, 14 or direct laser writing. 18 These techniques can generate nearly arbitrary patterns in resists (e.g., EBL) or hard materials (e.g., FIB milling), but they are serial, expensive, and require access to a cleanroom.…”