Ultra-compact Spatial Terahertz Switch Based on Graphene Plasmonic-Coupled Waveguide

We are proposing graphene (G)-based multilayered plasmonic spatial switch, operating at 10 THz. It is composed of hBN/Ag/hBN/G/hBN/G/hBN/SiO2/p(+)-Si multilayers. When a 10-THz transverse magnetic (TM)-polarized signal is normally incident upon the structure top surface, the nanoaperture devised in the Ag nanolayer, acting as a grating, excites surface plasmons at the top graphene micro-ribbons/hBN interface. These surface plasmons depending on the graphenes chemical potentials can be coupled to the lowerright or left graphene micro-ribbons and continue to propagate laterally towards the corresponding output port. Numerical simulations show that a change of Delta V-G approximate to +/- 2.7 Vin the voltage, applied to the gated micro-ribbons, can modulate their chemical potentials sufficiently to switch the right (left) output port fromON (OFF) toOFF(ON) and vice versa. Besides its low power consumption, the switch ultra-small dimensions make it a potential spatial router suitable for THz-integrated circuit applications.