Ultrasensitive sensor based on dynamic tunable dual plasmon-induced transparency of a three-graphene-layer structure

Abstract

Dual plasmon-induced transparency (PIT) is realized in the simple multilayer structure consisting of three graphene layers. The coupling mechanism between the three modes of three graphene layers is analyzed in detail. It is revealed that the dual PIT originates from the resonators with different quality factors by analog electromagnetic induction transparency (EIT) analysis and coupling mode theory (CMT). After that, the dual PIT expresses dynamic tunability by tuning applied bias voltage, which indicates that the structure proposed has potential application in modulators. Moreover, dual PIT in our proposed structure can be applied in the biosensor, and significantly improved sensitivity and figure of merit (FOM) as high as 16,660 nm/RIU and 31.0924 have been obtained, which has obvious enhancement compared with many reported sensors. This work can deepen our understanding of PIT and pave the way to the design of graphene dual PIT sensors.