High Efficiency Polarization‐Encoded Holograms with Ultrathin Bilayer Spin‐Decoupled Information Metasurfaces. Issue 5 (16th December 2020)

• Record Type: Journal Article
• Authors: Wang, Zheng Xing; Wu, Jun Wei; Wu, Liang Wei; Gou, Yue; Ma, Hui Feng; Cheng, Qiang; Cui, Tie Jun
• Is Part Of: Advanced optical materials. Volume 9:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-16
• Subjects: bilayer metasurfaces -- diffuse scattering -- high‐efficiency holography -- polarization‐encoded holograms -- spin‐decoupled information metasurface; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202001609
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Information metasurfaces, including digital coding and programmable metasurfaces, have reformed the design theory of metasurfaces from effective medium to coding pattern, and bridged the physical and digital world. Metasurface hologram has shown great potential in imaging and manipulating electromagnetic waves. In this work, bilayer information metasurfaces are proposed to achieve polarization‐encoded holograms in microwave regime. The designed metasurfaces consist of 3‐bit spin‐decoupled meta‐atoms, which possess ultrathin profiles (0.14λ0 ) and high cross‐polarization transmittance (over 0.8). The incident wave, which is right‐handed circularly polarized or left‐handed circularly polarized, is encoded with code "0" or "1". The spin‐decoupled design is combined with diffuse scattering and holographic technology. Based on this, a novel algorithm is proposed to generate coding sequences according to the code of incident wave, to achieve different functionalities for corresponding circularly polarized channels. In this way, polarization‐encoded holograms, including diffuse scattering holograms (code "00"), single channel holograms (code "01" or "10"), and spin‐selective holograms (code "11"), are achieved. Simulated and measured results show that the maximum imaging efficiency can reach up to 65.1%, verifying the high efficiency of this holographic technology. This work is expected to open a way of realizing more complicated and higher efficiency information metasurface holography. Abstract : In this paper, ultrathin bilayer spin‐decoupled information metasurfaces are designed. Using the metasurfaces, a new algorithm based on the combination of diffuse scattering method and holographic technology is proposed to achieve high efficiency polarization‐encoded holograms. The numerical simulations and experimental results agree well, and prove that the maximum imaging efficiency can reach up to 65.1%.