Isotropic Holographic Metasurfaces for Dual‐Functional Radiations without Mutual Interferences

Abstract

The dual‐functional and/or multifunctional devices have huge fascinations and prospects to conveniently integrate complex systems with low costs. However, most of such devices are based on anisotropic media or anisotropic structures. Here, a new method is proposed to design planar dual‐functional devices using an isotropic holographic metasurface, in which two different functions are written on the same holographic interference pattern with no mutual coupling. When the metasurface is excited by two orthogonally ported sources, the corresponding dual functions can be controlled by the object waves, which are not affected by each other due to suppression of mutual interference. The proposed metasurface is composed of subwavelength‐scale isotropic metallic patches on a grounded dielectric. In this specific design, double‐beam and double‐polarization radiate devices are realized independently by the orthogonal excitations. Based on the theoretical analysis, scanning radiate beams that are only controlled by frequency with different performances under orthogonal polarizations are demonstrated. To the best of our knowledge, this is the first time for actualizing dual‐functional devices using isotropic textures. Full‐wave simulations and experimental results in the microwave frequencies are presented to validate the proposed theory and confirm the corresponding physical phenomena.

Anomalous Refraction and Nondiffractive Bessel-Beam Generation of Terahertz Waves through Transmission-Type Coding Metasurfaces

“…For the reflection-type coding metasurfaces proposed in previous works, ,− unity reflection was readily achieved across the 2π phase coverage by a single metallic layer due to the presence of the metallic ground sheet. However, for the gradient-phase transmitarrays reported at terahertz and optical spectra using only a single metallic layer, − it is impossible for them to obtain 2π phase coverage together with sufficient transmittance.…”

Full-State Controls of Terahertz Waves Using Tensor Coding Metasurfaces

“…The PW–SW convertor proposed in this work, however, is able to convert both the x - and y -polarized normal incidences to SWs with TE and TM modes, which has not been reported before. Owing to the lack of efficient excitations of SWs at THz frequencies, many previous investigations on metamaterial-based SW manipulation devices were limited at the microwave frequency. ,,, The PW–SW convertor proposed in this work can be used as an efficient SW coupler and therefore may facilitate the design of spoof surface plasmon polariton , devices at THz frequencies. Interestingly, by combining the new PW–SW convertor with the previously reported one, one can design an SW splitter, which is able to separate the E x and E y polarizations included in the normal incidence to two TM-mode SWs traveling along opposite directions.…”

Wide dual-band dual-circularly polarized holographic metasurface

“…x + ϕ 2 y under the same g. In general, different resonances yield different transverse wave vectors, k t , thus leading to the radiation main beams steering, similar to the leaky wave antenna, against the operation frequencies [43,50,57,58,63]. To achieve stable radiations within a wide frequency band, the transverse wave vectors should be kept constant.…”