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Chamber of reflection sample12/26/2023 This phenomenon has been observed experimentally for anomalous reflection and refraction 21, 22, 23 and has been utilized to generate focused beams 24 and vortex beams 25, 26. The arrays of subwavelength-spaced scatterers, distributed on an ultrathin metasurface with a certain phase gradient, provide an added gradient wave vector, and thus alter the direction of the refracted beam, as determined by the generalized Snell’s law 11, 19, 20. Inspired by the generalized Snell’s law 11, ultrathin metamaterials or metasurfaces have been proposed to use discontinuous phase profiles for outgoing EM waves at the interface between two media 11, 12, 13, 14, 15, 16, 17, 18. Although the emergence of metamaterials and transformation optics offers new approaches for realizing many interesting devices, such as the perfect lens 5, invisibility cloaks 6, 7, 8, 9 and antennae 10, they still rely on the gradient phase accumulation along the beam path through three-dimensional (3D) metamaterials. Many exotic phenomena, such as negative refraction, subwavelength imaging and invisibility cloaking, have been experimentally demonstrated throughout the EM spectrum 1, 2, 3, 4. The unprecedented ability of metamaterials to manipulate electromagnetic (EM) waves in desired manners has provided a new route for designing strange devices, which has attracted much interest from both the physics and engineering communities. We believe that the proposed method may enable the digital coding metasurfaces to have broad applications in radar detections, wireless communications and imaging. With elaborately designed ellipse-shaped coding particles, we experimentally demonstrate various functions under oblique incidences, including the negative reflection of PW, negative SW, anomalous reflection and their arbitrary combinations, all having good agreements with theoretical and numerical predictions. On the basis of the digital description of coding metasurfaces, a simple coding method is proposed to allow dual functionalities (either PW or SW manipulations) under two orthogonal polarizations at arbitrarily oblique incidences, thus improving the adaptability of digital coding metasurfaces in more practical circumstances. Here, we experimentally demonstrate an anisotropic digital coding metasurface capable of controlling both PWs and SWs with a single coding pattern. Complete control of spatially propagating waves (PWs) and surface waves (SWs) is an ultimate goal that scientists and engineers seek for, in which negative reflection of PW and negative surface wave are two exotic phenomena.
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