Origami Metawall: Mechanically Controlled Absorption and Deflection of Light

The fruitful progress toward light manipulation in reflective (R) or transmissive (T) geometry (half‐space) has facilitated strong aspiration towards full‐space wave control. Although R–T synergistic strategy promises large‐capacity and integrated functionality, it imposes difficulty and challenges for direction of arrival (DoA) in full space via an ultrathin flat device. As of today, very limited demonstrations are reported for single‐wavelength and linear‐polarization operation in full space, significantly limiting the exploitable degrees of freedom (DoFs) for real‐world applications. Herein, a triple‐layer wavelength‐direction multitasking scheme for wide‐angle and large‐capacity DoA is reported, which is pivotal for blind‐free radar detection. By engineering two anisotropic sub‐meta‐atoms with high quality factor and simultaneous in‐plane and out‐of‐plane symmetry breaking, four R and two T spin‐conversion channels are achieved in wide‐angle operation with high efficiency and insulation. Above features and released DoFs would be extraordinarily beneficial for large‐capability and angle‐engineered advanced applications. Two proof‐of‐concept metadevices, i.e., a large‐scanning kaleidoscopic‐beam generator and a wide‐angle reverser for multi‐target tracking, are devised to verify the significance. Numerical and experimental results show predesigned functions at six channels with measured efficiency over 75%. The findings in achieving multi‐DoF multitasking can stimulate great interest in radar applications with versatile forming beams and multi‐channel integration.

Section: Wide‐angle Large‐capacity Reversermentioning

confidence: 99%

Section: Wide‐angle Large‐capacity Reversermentioning

confidence: 99%

Spin‐Encoded Wavelength‐Direction Multitasking Janus Metasurfaces

Wang

et al. 2021

“…[ 18 ] However, the EM properties of the aforementioned passive metasurfaces are determined by structure parameters, so that the manipulation of EM wave is fixed once the design is completed. Recently, much attention has been paid on active metasurfaces whose operation status can be dynamically controlled by mechanical deformation, [ 19 ] phase changing materials [ 20–22 ] or active components. [ 23 ] In particular, liquid crystal and chalcogenide arguably exhibit the phase‐change phenomena which can be externally controlled by temperature, light, and electric or magnetic fields, making them promising candidates to develop reconfigurable terahertz metasurfaces.…”

Section: Figurementioning

confidence: 99%

Dynamic Scattering Steering with Graphene‐Based Coding Metamirror

Zhang

Yang

et al. 2020

116

Over last two decades, metamaterials have gained considerable momentum and emerged as one of the most promising area of electromagnetics. [1,2] Metamaterials are composed of artificially periodic metallic or dielectric structures with subwavelength scale which enable us to achieve unique electromagnetic (EM) properties such as perfect absorption [3] and negative refraction. [4] Despite the success of metamaterials in fundamental physics, devising metamaterials for real applications still remains a big challenge due to their large volume and complex fabrication. Metasurfaces, the 2D equivalence of metamaterials with planar profile, serve as an alternative approach to bypass the volume

“…Metasurfaces, a 2D form of metamaterials, have made rapid development with the advantages of powerful ability to manipulate EM waves and the advantages of compact size, low loss, easy manufacture. [ 3–37 ] The proposal of the generalized Snell's laws [ 3 ] leads to the unprecedented development of metasurface, and many fascinating phenomena are achieving, such as random diffusions, [ 4–6 ] orbital angular momentum, [ 7 ] beam deflection, [ 8–11 ] vortex beams, [ 12–14 ] wavefront manipulation, [ 15–17 ] and holograms. [ 18–19 ]…”

Section: Introductionmentioning

confidence: 99%

Multidimensionally Manipulated Active Coding Metasurface by Merging Pancharatnam–Berry Phase and Dynamic Phase

Jiang

Jing

et al. 2021

Multidimensionally (amplitude, polarization, and phase) manipulated metasurfaces have drawn more significant advantages in modern photonic applications. In this paper, the active multidimensionally manipulated metasurface merging Pancharatnam–Berry phase and dynamic phase is proposed. The phase and polarization of the coding elements here can be adjusted dynamically by utilizing positive‐intrinsic‐negative (PIN) diodes. More remarkably, the independent feeding of the coding elements in two layers is creatively proposed so that each coding element of the active coding metasurface (ACM) has four basic response states. And the four states can be dynamically switched by regulating the bias voltages imposed on the PIN diodes through field programmable gate array (FPGA). Therefore, the versatile functionalities of the ACM are achieved and all the functionalities can be implemented in real‐time. As a proof of concept, three specific functionalities are validated both from the simulation and measurement on a fabricated prototype with good coincidence with each other. The ACM can achieve copolarization, crosspolarization anomalous reflection, and circular‐linear polarization conversion for the incident circularly polarized wave. The proposed ACM opens new vistas in active metadevices and has broad application prospects in multifunctional devices and communication systems.