Independent and Free Control of Multiple Beams Enabled by Wideband Spin‐Decoupled Metasurface

Abstract

Pancharatnam–Berry (PB) phase is typically employed to control circularly polarized (CP) waves, but it has spin‐locked limitations due to its conjugate phase response to different spins. Recently, by modulating both propagation and PB phases, spin‐decoupled metasurfaces have attracted much attention. Most of these spin–decoupled metasurfaces are realized by regulating co‐polarized components, which need N meta‐atoms to achieve a 360° phase coverage. However, this research on wideband high‐efficiency spin‐decoupled metasurfaces based on polarization conversion meta‐atoms by adjusting cross‐polarized components is still lacking. Compared with the regulation of co‐polarized components, only N/2 meta‐atoms are needed for the regulation of cross‐polarized components, which greatly reduces the design difficulty. Here, two spin‐decoupled metasurfaces are proposed for the generation of multiple vortex beams and pencil beams, which exhibit broadband and high‐efficiency performance at the frequency range of 9–21 GHz. This work has the potential to significantly promote the development of wideband polarization multiplexing and multichannel meta‐devices, with various applications in cyberspace security, wireless communication, imaging, and target detection.