Reconfigurable Terahertz Quarter-Wave Plate for Helicity Switching Based on Babinet Inversion of an Anisotropic Checkerboard Metasurface

Abstract

Dynamic helicity switching by utilizing metasurfaces is challenging because it requires deep modulation of polarization states. To realize such helicity switching, this paper proposes a dynamic metasurface functioning as a switchable quarter-wave plate, the fast axis of which can be dynamically rotated by 90 • . The device is based on the critical transition of an anisotropic metallic checkerboard, which realizes the deep modulation and simultaneous design of the switchable states. After verifying the functionality of the ideally designed device in a simulation, we tune its structural parameters to realize practical experiments in the terahertz frequency range. By evaluating the fabricated sample with vanadium dioxide, the conductivity of which can be controlled by temperature, its dynamic helicity switching function is demonstrated.

Terahertz Metasurfaces: Toward Multifunctional and Programmable Wave Manipulation

“…Further, the authors discussed the meta-lens with distinguished abilities in focal length tuning, wideband focusing, and wide-angle focusing shifting. In addition to the above two functions, active metasurfaces have also been exploited to achieve absorbing [81][82][83], beam steering [42,[84][85][86][87], polarization switching [88,89], imaging [90], and so on.…”

Geometric Structure behind Duality and Manifestation of Self-Duality from Electrical Circuits to Metamaterials

“…The criticality of metallic checkerboard-like metasurfaces is utilized for dynamical metasurfaces to manipulate electromagnetic waves. By placing photoconductive materials like silicon or phase-change materials like vanadium dioxide (VO 2 ) between the metallic patches of checkerboard-like metasurfaces, researchers have realized optically tunable waveguides [99], capacitive-inductive switchable filters [50], dynamical polarizers [49], and dynamical switching of quarter-wavelength plates [52]. In addition to these experiments, dynamical planar-chirality switching is also theoretically proposed [51].…”

“…Over the past few decades, duality has been assuming an important role in the research and development of metamaterials. To name a few such cases, duality has been leveraged to design complementary metasurfaces [32][33][34][35], self-complementary metasurfaces [36][37][38][39][40][41][42], critical metasurfaces [43][44][45][46][47][48][49][50][51][52], maximally chiral metamaterials [53], and self-dual metamaterials with zero backscattering [54] or helicity conservation [55][56][57]. In such situations, the extensive target frequencies of metamaterials require a comprehensive understanding of duality in a unified manner.…”

Anisotropic Temporal Metasurfaces for Tunable Ultrafast Photoactive Switching Dynamics

“…Metasurfaces, which can be viewed as two‐dimensional counterparts of metamaterials, are planar optical components consisting of artificially designed building blocks that enable unprecedented control of electromagnetic waves. Many advancements have already been achieved in metasurfaces‐related applications, such as anomalous refraction or reflection, [ 1,2 ] ultrathin superlenses, [ 3,4 ] novel quarter‐wave plates, [ 5 ] vortex beam generation, [ 6,7 ] polarization control [ 8,9 ] and high‐resolution holograms. [ 10,11 ] However, the optical properties of passive metasurfaces remain unchanged once fabricated.…”