On-chip multidimensional dynamic manipulation of terahertz spoof surface waves based on graphene metasurfaces

The multidimensional dynamic manipulation of spoof surface waves (SSWs) is crucial for terahertz (THz) on-chip integrated systems. However, existing metasurfaces are limited to passive, single-function wavefront shaping of SSWs, which precludes on-chip multidimensional dynamic control and hinders their practical applications. To address these limitations, we propose a polarization multiplexing THz graphene metasurface. This structure comprises two key sections: a central metacoupler composed of graphene-integrated cross-shaped meta-atoms that excites SSWs, and flanking plasmonic metal regions that support the SSW propagation along the interface. By tuning the dimensions and rotation angles of the cross-shaped meta-atoms along with the graphene Fermi level, the metasurface enables polarization multiplexing, spatial wavefront shaping, and amplitude modulation of the SSWs under orthogonal circular polarization (CP) incidences simultaneously. To validate this design, we experimentally fabricated the graphene metasurface, achieving multidimensional dynamic control of a spoof surface focusing beam (SSFB) and a spoof surface Bessel beam (SSBB) under different CP illuminations. Therefore, the scheme realizes on-chip multidimensional dynamic manipulation of SSWs, offering significant potential for THz on-chip communication and integrated photonic applications.