Super Subwavelength Guiding and Rejecting of Terahertz Spoof SPPs Enabled by Planar Plasmonic Waveguides and Notch Filters Based on Spiral-Shaped Units

Curved terahertz surface plasmonic waveguide devices

“…Among the proposed spoof SPP waveguides, various groove or pillar structures providing high field confinement have been proposed [18][19][20][21][22] and demonstrated by near field detection techniques in THz regime [23,24]. Meanwhile, different spoof SPP functional devices such as amplifiers, wavelength filters, and sharp bends, have also been reported [25][26][27][28][29][30]. Nevertheless, it is still a great challenge to design and realize compact, low bending loss and high-precision THz integrated circuits, and this is further complicated by the fact that any practical integrated system may have curved connecting sections.…”

Routing of strongly confined terahertz spoof surface plasmon polaritons on metasurfaces along straight and curved pathways with subwavelength width

“…These surface waves with emulated SPP characteristics are called spoof surface plasmon polaritons (SSPPs) [10]. Various metasurface structures that enable SSPP modes, such as planar metamaterials composed by split-ring-resonators [11][12][13], H-shaped patches [14][15][16] or similar metallic patterns [17][18][19][20][21][22][23][24][25] as well as corrugated metal surfaces with grooves and pillars [6,7,[26][27][28][29][30][31][32][33], were proposed in recent years. While metasurfaces composed of ultrathin metallic patterns can be directly processed on printed circuit boards (PCBs) or can be manufactured by straight forward fabrication techniques, corrugated metal surfaces with groove depths of up to several hundred micrometers cannot lean on easy technologies and require more sophisticated fabrication methods.…”

“…In highly integrated circuits however, it is mandatory that the metasurface structures also confine the SSPPs within the plane of propagation on a subwavelength scale and allow deliberate waveguiding and routing of the SSPPs on pathways with subwavelength path width. In this context, latest research that covers such flat and compact sized metasurface structures at terahertz frequencies lack experimental evaluation [20][21][22]. They are either restricted to numerical simulation models [20,22] or they only deliver simple proof-in-principle demonstrations in the microwave regime [21].…”

“…In this context, latest research that covers such flat and compact sized metasurface structures at terahertz frequencies lack experimental evaluation [20][21][22]. They are either restricted to numerical simulation models [20,22] or they only deliver simple proof-in-principle demonstrations in the microwave regime [21]. For this reason, it was our goal to design and fabricate ultrathin metasurfaces with tailored dispersion to gain full control over the in-plane propagation of terahertz SSPPs, while still maintaining a subwavelength field confinement to the metasurface.…”

Novel crest‐trough shaped spoof surface plasmon polaritons for low pass filtering applications

“…However, metal behaves as perfect electric conductor at microwave, terahertz, and far‐infrared regimes and this drawback has been overcome by the concept of spoof SPPs (SSPPs) . These highly confined surface waves mimic the properties of SPPs, realized by surface decorations of subwavelength periodic grooves or holes and their dispersion properties can conveniently be controlled simply by adjusting the geometric parameters . Corrugated planar metallic strips manufactured by standard PCB fabrication technology are the focus of plasmonic metamaterial community due to simple and low‐cost fabrication, flexibility, low‐loss, and reduced interference.…”