Metamaterial-mediated terahertz surface waves with strong confinement

Abstract

We present experimental und numerical investigations on the excitation, optimization and propagation of terahertz surface waves on silicon substrates. A single metamaterial layer is used to enhance the spatial confinement of the surface wave at the interface between air and silicon. The electric terahertz field of the surface wave is measured by a 2D near field scan.

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.…”

“…While these metasurfaces provide favorable properties in a manifold context, past reports in the literature only focused on the demonstration of very few aspects as they mostly investigate the propagation of SSPPs along straight pathways. Frequently, the SSPPs are well bound in the direction perpendicular to the surface, yet are completely unconfined in the plane in which they propagate [11][12][13][16][17][18]. 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.…”