Plasmonic Tuning at Mid-Infrared Wavelengths by Composite Arrays of Graphene Ribbons

This work reports on a numerical simulation study regarding the systematic tuning of plasmonic resonance wavelength in the mid-infrared regime, by using composite arrays of graphene ribbons. On top of a glass substrate, a variety of composite arrays that consist of graphene ribbons are carefully designed. The layer numbers of the multi-layer graphene ribbons and the Fermi energy levels of the graphene are respectively varied, and the corresponding light transmittance is calculated in the mid-infrared wavelength range from 4 to 20 mu m, via the finite difference time domain (FDTD) method. The results reveal that the plasmonic resonance wavelength associated with the graphene arrays can be tuned in the mid-infrared wavelength range by adjusting the parameters of the arrays. Based on the study, we suggest that the structure of the graphene composite arrays proposed in this work be implemented in the design for plasmonic tuning devices at mid-infrared wavelengths.