A quintuple plasmon-induced transparency multifunction switch based on the polarization-sensitive graphene-based metamaterial

Abstract

A monolayer metamaterial consisting of a rectangle graphene strip and four L-shaped graphene blocks was proposed to achieve a quintuple plasmon-induced transparency (quintuple-PIT). The numerical simulation results based on the finite difference time domain method agree well with the calculated results of the coupled mode theory. By modulating the Fermi energy level of graphene, an octuple-frequency asynchronous switch and a sextuple-frequency synchronous switch are designed and studied, which have excellent amplitude modulation degree (up to 97.7%), extinction ratio (up to 16.41 dB), insertion loss (low to 5.4%), and dephasing time(low to 3.86 ps). Furthermore, the results show that the proposed metamaterials has polarization-sensitive characteristics due to their non-central symmetry. Further research shows that the group index is as high as 604 which has a good slow light effect and can be used for optical storage. Hence, the quintuple-PIT proposed structure in this paper has good application value in the expansion of multi-function optical switches and the research of high-quality optical memory.