Spoof surface plasmon polaritons supported by ultrathin corrugated metal strip and their applications

In this review, we present a brief introduction on the spoof surface plasmons supported on corrugated metallic plates with nearly zero thickness. We mainly focus on the propagation characteristics of spoof surface plasmon polaritons (SPPs), excitation of planar SPPs, and several plasmonic devices including the bending waveguide, Y-shaped beam splitter, frequency splitter, and filter. These devices are designed and fabricated with either planar or conformal plasmonic metamaterials, which are validated by both full-wave simulations and experiments, showing high performance. We also demonstrate that an ultrathin textured metallic disk can support multipolar spoof localized surface plasmons, either with straight or curved grooves, from which the Fano resonances are also observed.