Abstract-Curved terahertz surface plasmonic waveguide devices

Mingrui Yuan, Yongchang Lu, Ying Zhang, Ziying Zhang, Yanfeng Li, Hongchao Liu, Xixiang Zhang, Jiaguang Han, Weili Zhang,

Structure and dispersion relation. (a) Schematic diagram and geometric parameters of the structure (the red arrow depicts the propagation direction of SPPs). The lower left inset shows the SEM image of the fabricated arc-shaped curved hole array excitation region as well as the fan-shaped coupling region. The lower right inset shows the fabricated waveguide structure. (b) The simulated dispersion relation (red line) of SPP mode for one row of metal pillars.

https://www.osapublishing.org/oe/abstract.cfm?URI=oe-28-2-1987

Strongly confined surface waves can be achieved on periodically structured metal surfaces and are known as spoof surface plasmon polaritons (SPPs). In this work, several terahertz SPP devices based on curved waveguides are demonstrated. The transmittance and bending loss of 90-degree curved spoof SPP waveguides with a radius of curvature ranging from 200 to 2300 µm are investigated to identify the regime for high transmission. A commutator is designed and experimentally demonstrated. Furthermore, coupling equations are derived and verified for efficient coupling between bend-straight waveguides and between bend-bend waveguides. The results will be of great value for future integrated terahertz plasmonic systems.

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