Spoof Plasmonic Metasurfaces with Catenary Dispersion for Two-Dimensional Wide-Angle Focusing and Imaging

Although tremendous efforts have been devoted to investigating the analogy between the surface plasmon polariton and its spoof counterparts, it remains elusive that a single thin spoof plasmonic metalens realizes wide-angle focusing and wide field-of-view (FOV) imaging. Here, we propose a spoof plasmonic metasurface that can impart arbitrary phase with high transmittance, which comprises two-dimensional (2D) gradient spoof-insulator-spoof waveguides. With the developed catenary field and dispersion theory, their intrinsic physics is theoretically analyzed. As a proof of concept, a spoof plasmonic metalens with a thickness of 0.15 lambda has been elaborately designed and experimentally demonstrated for wide-angle (similar to 170 degrees) focusing and wide FOV (similar to 40 degrees) imaging. To the best of our knowledge, it is the first experimental demonstration of wide FOV imaging of a 2D object with single thin and planar metalens in the microwave regime The proposed method offers a promising solution to compact cameras, integrated imaging, and detection systems.