On‐Chip Multi‐Channel Wavefront Manipulation of Spoof Surface Waves With Structural Heterogeneous Metasurfaces

Abstract Due to their localized field enhancement and subwavelength resolution, spoof surface waves (SSWs) hold broad application prospects in communications, sensing, and photonics through on‐chip wavefront manipulation. However, conventional metasurfaces for SSW wavefront shaping are typically limited to single‐frequency or single‐multiplexing operation, restricting the development of large capacity on‐chip integrated devices. To overcome these limitations, we proposed a structural heterogeneous metasurface comprising a central metacoupler flanked by two plasmonic guiding regions for on‐chip multi‐channel SSW wavefront manipulation. In this structure, the metacoupler consists of the structural heterogeneous meta‐atoms featuring a curved I‐shaped structure embedded within a double‐split ring. By independently adjusting the opening and rotation angles of both double‐split ring and curved I‐shaped elements, full 2π phase coverage is obtained for two distinct operating frequencies and orthogonal circular polarization waves, thereby enabling polarization‐frequency multiplexing. Leveraging this design, we experimentally demonstrated a structural heterogeneous metasurface capable of generating a spoof surface deflected beam, a spoof surface Bessel beam, a spoof surface focusing beam, and a spoof surface Airy beam at two frequencies under circular polarization illumination. Therefore, the structural heterogeneous metasurface provides a versatile platform for multi‐channel SSW wavefront manipulation, with significant potential for large capacity on‐chip communications and integrated photonic systems.