Ultrathin metasurface with topological transition for manipulating spoof surface plasmon polaritons

摘要

Metasurfaces, with intrinsically planar nature and subwavelength thickness,provide us unconventional methodologies to not only mold the flow ofpropagating waves but also manipulate near-field waves. Plasmonic metasurfaceswith topological transition for controlling surface plasmon polaritons (SPPs)recently have been experimentally demonstrated, which, however, are limited tooptical frequencies. In this work, we proposed and experimentally characterizedan ultrathin metasurface with the topological transition for manipulating spoofSPPs at low frequency. We demonstrated rich interesting phenomena based on thismetasurface, including frequency-dependent spatial localization,non-diffraction propagation, negative refraction, and dispersion-dependentspin-momentum locking of spoof SPPs. Comparing with traditionalthree-dimensional metamaterials, our metasurface exhibits low propagation lossand compatibility with the photonic integrated circuit, which may find plentyof applications in spatial multiplexers, focusing and imaging devices, planarhyperlens, and dispersion-dependent directional couplers, in microwave andterahertz frequencies.