Tunable artificial chirality with extraordinary transmission metamaterials

Abstract

We propose the design of a three-dimensional anisotropic chiral structure composed of double-layered metallic films. Each layer behaves as a half-wave plate thanks to the excitation and the propagation of guided modes inside the subwavelength apertures of each metallic layer. As in conventional optics, the optical rotation is tuned by simply changing the angle between the two plates. We numerically demonstrate that this property remains valid only if the whole second layer is rotated instead of twisting every pattern. Therefore, the plane of polarization can be rotated by any desired value and is accompanied by a transmission up to 80%. The proposed structure opens the way to the design of a new kind of chiral plate in the terahertz or microwave domains.

Pseudospin‐Mediated Optical Spin–Spin Interaction in Nonlinear Photonic Graphene

“…Since initially demonstrated, chiral metamaterials have attracted much attention and various types of chiral metamaterials have been reported from microwave, terahertz to optical frequency regimes . While most of the chiral metamaterials demonstrated so far have a fixed chirality, there have been a number of demonstrations of active or switchable chiral metamaterials, which exhibit change of chirality under the excitation of external stimuli, such as optical pumping, applied voltage, magnetic field, and hydrogen‐regulation . However, these engineered chiral metamaterials generally require an array of bilayer metallic structures or even more complex three‐dimensional (3D) metallic chiral structures, which increase the difficulty of device implementation.…”

Spectrally tunable linear polarization rotation using stacked metallic metamaterials

“…and |β − 1| 2 spectrum (green curve) which let appear two resonances. The peak close to λ/p = 1.76 is related to the cut-off of the T E 01 and the peak close to λ/p = 1.46 refers to its first Fabry-Perot-like resonance 33 .…”

Artificial Chiral Nanostructure at Oblique Incidence

“…The optical rotation will be obtained after calculating the transmission spectra for two incidents orthogonal (p and s) polarization states [5]. The transmitted field components are connected to the incident field ones by the transmission Jones matrix T (in the straight-line basis).…”

“…The emergence of nano-optics in recent decades has attracted scientists in the electromagnetic field and tried to generate artificial optical activity (chirality) using the original properties exhibited by metamaterials. Consequently, the main objective in the development of artificial chiral periodic structures is to produce simultaneously a large optical activity and a high transmittance [5]. In 1920, Lindman [6] announced the first artificial chiral isotropic medium by studying the randomly oriented collections of metal helices size of the wavelength.…”

“…The optically D DAVID PUBLISHING active media are used as polarization rotators and also circular polarizers [7]. In 2012 we designed an artificial chiral structure based on two identical half-wave plates (λ/2) after rotating one of them by an angle α with regard to the other (at normal incidence) [5]. A tuneable rotation (Ø) corresponding to two times the angle (α) between the two plates is checked with enhanced transmission (> 80%) at the working wavelength.…”