Generating dual-polarization beams carrying dual orbital angular momentum modes based on anisotropic holographic metasurfaces

Abstract

Abstract Through this study, we demonstrate the generation of linear dual-polarization beams with different orbital angular momentum (OAM) modes by designing, manufacturing, and experimentally measuring an anisotropic holographic metasurface. A combination of the leaky-wave theory and the microwave holographic method is proposed as a way to effectively construct the metasurface based on the interferogram obtained by the interference between the surface waves excited by a monopole and our predesigned OAM beams. In addition, the inhomogeneous holographic metasurface is composed of massive square metallic patches of different dimensions on a grounded substrate, and the anisotropy of the different particles is characterized by the different orientation angles of the rectangular slots that are etched on the upper metallic layer. The close agreement between the numerical simulations and experimental measurements verify the good performance of the metasurface. This finding creates a new opportunity to generate dual-polarization dual-OAM modes for radio vortex beams and lays a solid foundation for multiple OAM modes in wireless communication systems.