Tunable multiple channeled phenomena in graphene-based plasmonic Bragg reflectors

Plasmonic Bragg reflectors based on graphene with multiple channeled phenomena are proposed and investigated numerically. As a mid-infrared waveguide, the monolayer graphene exhibits locally variable optical properties through the modulation of electric fields. The periodical change of the effective refractive index (ERI) on graphene can be determined by applying external gate voltage. When we introduce an unmatched configuration or gate voltage, periodicity is disrupted, and a defect resonance mode is generated. At this point, the structure can be regard as a Fabry-Perot cavity. Accordingly, multiple-channel effects can be achieved by introducing cascaded multiple defects or including double symmetrical Fabry-Perot structures. This design shows applications potential in the graphene-based optoelectronic devices, particularly in the development of low-cost hyperspectral imaging sensors in mid-infrared region