Invisible surfaces enabled by the coalescence of anti-reflection and wavefront controllability in ultrathin metasurfaces

Abstract

Reflection inherently occurs on the interfaces between different media. In order to perfectly manipulate waves on the interfaces, integration of antireflection function in metasurfaces is highly desired. In this work, we demonstrate an approach to realize exceptional metasurfaces that combine the two vital functionalities of antireflection and arbitrary phase manipulation in the deep subwavelength scale. Such ultrathin devices confer reflection-less transmission through impedance-mismatched interfaces with arbitrary wavefront shapes. Theoretically and experimentally, we demonstrate a three-layer antireflection metasurface that achieves an intriguing phenomenon: the simultaneous elimination of the reflection and refraction effects on a dielectric surface. Incident waves transmit straightly through the dielectric surface as if the surface turns invisible. We further demonstrate a wide variety of applications such as invisible curved surfaces, “cloaking” of dielectric objects, reflection-less negative refraction and flat axicons on dielectric-air interfaces, etc. The coalescence of antireflection and wavefront controllability in the deep subwavelength scale brings new opportunities for advanced interface optics with high efficiency and great flexibility.

Advances in Meta-Optics and Metasurfaces: Fundamentals and Applications

“…Metasurfaces with multi-functional wavefront control show the significant superiority of meta-optics [ 109 ]. Generally, anisotropic and sub-wavelength meta-atoms act as waveplates due to their vastly different responses to orthogonal polarizations [ 55 ].…”

“…Recent advances in meta-optics have been applied in the demonstrations of many exotic optical manipulations and various useful meta-devices [ 101 , 102 , 103 , 104 , 105 , 106 ]. Metasurface-based applications are promising alternatives to replacing existing optical devices, owning to the ultrathin, ultracompact, and multifunctional properties of meta-devices based on the principles of meta-optics [ 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 ]. Meta-optics offer the possibility to address the limitations of conventional optics and a new paradigm to achieve on-chip integrated meta-devices with multi-functional and parallel control of light beams [ 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ].…”

Manipulating light transmission and absorption via an achromatic reflectionless metasurface

“…However, strong reflections always appear in such meta-devices at frequencies out of their narrow working bands in which perfect absorption/transparency is achieved. Recently, A few attempts appear to construct reflectionless metasurfaces based on different approaches such as antireflection coating [29,30], anomalous Brewster effect [31,32], specular reflection reduction [33], etc. One typical design approach is to put into a unit cell two resonators, exhibiting electric and magnetic responses, respectively, so that their back scatterings can exactly cancel each other under certain condition (e.g., the Kerker condition [34][35][36][37]).…”

2D MXene Ti3C2Tx Enhanced Plasmonic Absorption in Metasurface for Terahertz Shielding

“…THz shielding is also excellent in 2D materials, which can effectively combine the intrinsic properties [15] with the structural qualities of 2D materials [16]. In the terahertz region, these innovative 2D structures can maximize impedance matching conditions and enable multiple terahertz scattering responses, resulting in high absorption efficiency with active control of shielding performance [17].…”

“…In the terahertz region, these innovative 2D structures can maximize impedance matching conditions and enable multiple terahertz scattering responses, resulting in high absorption efficiency with active control of shielding performance [17]. MXenes are a new family of 2D materials exhibiting high conductivity [18], high strength [19], ultra-thinness [15], and tunable electromagnetic responses [20] have shown better performance in the terahertz region [19]. The better performance has encouraged researchers to realize broadband terahertz absorbers for shielding applications.…”