Ultra-Compact Bidirectional Terahertz Switch Based on Resonance in Graphene Ring and Plate

In this paper, we present a switch based on coupling and resonance in thegraphene plate and rings operating at 10 THz. This structure consists of several layers ofHexagonal Boron Nitride (hBN), SiO2 and P+Si, such that graphene plates and rings areinside the hBN layer. The terahertz wave is incident from the upper part of the switchand Surface Plasmons (SPs) are excited by the grating in the structure on the grapheneplate beneath the nano-aperture and moves towards the ports available on the left andright of the switch. At first, at the certain applied voltage, the SPs cross the left port andthis port is ON. With the increase in voltage and the change in the chemical potential,switching occurs and the SPs exit from the right and this port is ON while the left portturns OFF. The extinction ratio in this structure is 18dB and the size of the structure is1μm. Aforementioned benefits make this switch the best choice for using in integratedoptical circuits.