Mid-Infrared Tunable Dual-Frequency Cross Polarization Converters Using Graphene-Based L-Shaped Nanoslot Array

In this paper, we proposed a novel dual-frequency cross polarization converter that can simultaneously work at two frequencies in the reflection mode, which is constructed of an L-shaped perforated graphene sheet printed on a dielectric material backed by a gold ground plane. For the normal incidence, the optical rotation at these two working frequencies originates from the simultaneous excitation of both eigen-modes that are characterized as the results of the localized surface plasmon resonances. Moreover, by merely varying the Fermi energy of the graphene, both working frequencies can be tuned within a large frequency range, which suggests numerous potential optical applications.