Spoof surface plasmon photonics

Abstract

In undergraduate courses on classical electromagnetism, it is taught that a perfect conductor expels the electromagnetic (EM) field, and hence its surface is not able to support the propagation of bound EM waves. However, when the surface of a perfect conductor is structured at a length scale much smaller than the operating wavelength, geometrically induced surface EM modes can be supported. Owing to their similarities with the surface plasmon polaritons (SPPs) in the optical regime, these surface EM modes were named spoof surface plasmons. The concept of spoof surface plasmons has opened up a new line of research within plasmonics with the aim of transferring all the potentialities of SPPs in the optical regime to lower frequencies (microwave, terahertz, and midinfrared regimes) in which a metal behaves as a quasiperfect conductor. In recent years, several research groups have extended this concept from planar surfaces to waveguides, and eventually to resonators, covering the entire range of structures studied in standard plasmonics. This review provides a detailed perspective on the recent developments in spoof surface plasmon photonics from both the fundamental and applied sides.

Near-field chiral excitation of universal spin-momentum locking transport of edge waves in microwave metamaterials

“…56,57 The scale of semiconductor devices is much smaller than the wavelength; therefore, it is crucial to explore device-assisted metamaterials beyond the conventional structural designs. Recently, plenty of exotic spoof SPPs components have been reported, 58 such as parametric amplifiers, 59 active Fano sensors, 60 and nonlinear harmonic generators. 61 Compared to vigorous active spoof SPPs, the device-assisted technology is still a virgin land in LWs and PTIs because they require loading devices in the form of 2D arrays.…”

Radio-frequency sheath excitation at the extremities of scrape-off layer plasma filaments, mediated by resonant high harmonic fast wave scattering

“…The FAMC modes are similar to surface plasmons propagating along planar or patterned dielectric/metal interfaces (Raether 1988; Garcia-Vidal et al. 2022) or near the boundaries of plasma-filled waveguides (Girka & Thumm 2022). One can see the FAMC modes as a generalization of plasmons to cylindrical interfaces in magnetized plasmas, allowing for curvature effects and mode mixing in the HHFW regime.…”

“…Tierens et al (2020aTierens et al ( ,b, 2022a proposed a more efficient process: evanescent filament assisted mode conversion (FAMC) modes produced by the nearly resonant scattering of High Harmonic Fast Waves (HHFW) off cylindrical field-aligned density inhomogeneities (likely turbulent 'filaments'). The FAMC modes are similar to surface plasmons propagating along planar or patterned dielectric/metal interfaces (Raether 1988;Garcia-Vidal et al 2022) or near the boundaries of plasma-filled waveguides (Girka & Thumm 2022). One can see the FAMC modes as a generalization of plasmons to cylindrical interfaces in magnetized plasmas, allowing for curvature effects and mode mixing in the HHFW regime.…”

Enhancing directivity of terahertz photoconductive antennas using spoof surface plasmon structure

“…Here, we propose a scheme to increase the directivity of PCAs in a broad band, by incorporating spoof surface plasmon polariton (SSPP) [33][34][35] structures in PCAs. The SSPP structure is a subwavelength metallic grating, which can host surface electromagnetic (EM) modes, analogous to surface plasmon polariton (SPP) in nano optics [36][37][38].…”