Ultra-thin and high-efficiency full-space Pancharatnam-Berry metasurface

Abstract

Full-space metasurfaces (MSs) attract significant attention in the field of electromagnetic (EM) wave manipulation due to their advantages of functionality integration, spatial integration and wide applications in modern communication systems. However, almost all reported full-space metasurfaces are realized by multilayer dielectric cascaded structures, which not only has the disadvantages of high cost and complex fabrication but also is inconvenient to device integration. Thus, it is of great interest to achieve high-efficiency full-space metasurfaces through simple design and easy fabrication procedures. Here, we propose a full-space MS that can efficiently manipulate the circularly polarized (CP) waves in dual frequency bands by only using a single substrate layer, the reflection and transmission properties can be independently controlled by rotating the optimized meta-structures on the metasurface. Our full-space metasurface has the potential to design multifunctional devices. To prove the concept, we fabricate the device and measured it in microwave chamber. For the reflection mode, our metasurface can behave as a CP beam splitter at the frequency of f1 = 8.3 GHz and exhibit high efficiencies in the range of 84.1%–84.9%. For the transmission mode, our metasurface acts as a meta-lens at the frequency of f2 = 12.8 GHz for the LCP incidence, and the measured relative efficiency of the meta-lens reaches about 82.7%. Our findings provide an alternative way to design full-space metasurfaces and yield many applications in EM integration systems.

Ultrathin Dual‐Band Wide‐Angle Beam Scanning Metalens Based on High‐Efficiency Meta‐Atom

“…Although single-layer substrate is also used in refs. [13,16,[30][31][32], none of them focus on the wide-angle beam scanning function at two bands simultaneously. Moreover, the scanning coverages in other works are less than AE45 , which requires at least four sections for realizing the full 360 scanning.…”

“…While for the one with Fourier phase distribution in Figure 4a, both the normal and oblique incidences could be well converged to the focal plane. [ 31 ] Hence the FoV of the metalens is effectively extended due to the aspherical property of Fourier phase distribution. Formula of such phase distribution can be derived from a general case of oblique incidence by geometry optics (GO) method.…”

“…In ref. [31], a high‐efficiency full‐space metasurface composed of bilayer meta‐atom is proposed to act as a meta‐lens and a beam‐splitter at two specific bands, respectively. In ref.…”

High‐Efficiency Full‐Space Complex‐Amplitude Metasurfaces Enabled by a Bi‐Spectral Single‐Substrate‐Layer Meta‐Atom

“…[ 36,37 ] Furthermore, multi‐band full‐space metasurfaces for the CP wave are also designed with phase only control. [ 38–41 ] It is noted that multi‐band full‐space complex‐amplitude metasurfaces are still in their infancy and remain elusive due to the coupling between resonators and the complexity of the design process of the meta‐atom.…”

Ultrathin and high-efficiency Pancharatnam–Berry phase metalens for millimeter waves

“…Nevertheless, there are experimental and numerical demonstrations of bi-layer PBMs designs in the literature: a vortex generator that achieves a transmission efficiency of 55% (with a thickness λ/20) 17 , a beam steerer with a transmission efficiency of 80% (thickness below λ/10) 13 , and recently, a PB metalens with a cross-polar transmission efficiency of 82.7% (thickness below λ/8 25 ). Although all these works achieve very high-efficiency values, all of them are below the best tri-layer designs 18 .…”