High-sensitive refractive index sensing and excellent slow light based on tunable triple plasmon-induced transparency in monolayer graphene based metamaterial

A patterned monolayer graphene metamaterial structure consisting of six graphene blocks and two graphene strips is proposed to generate triple plasmon-induced transparency (PIT). Triple-PIT can be effectively modulated by Fermi levels of graphene. The theoretically calculated results by coupled mode theory show a high matching degree with the numerically simulated results by finite-difference time-domain. Intriguingly, the high-sensitive refractive index sensing and excellent slow-light performance can be realized in the proposed graphene metamaterial structure. The sensitivity (S) and figure of merit can reach up to 5.7115 THz RIU^?1 and 116.32, respectively. Moreover, the maximum group refractive index is 1036. Hence, these results may provide a new idea for designing graphene-based sensors and slow light devices.