Manipulating the interaction between localized and delocalized surface plasmon-polaritons in graphene

The excitation of localized or delocalized surface plasmon-polaritons in nanostructured or extended graphene has attracted a steadily increasing attention due to their promising applications in sensors, switches, and filters. These single resonances may couple and intriguing spectral signatures can be achieved by exploiting the entailing hybridization. Whereas thus far only the coupling between localized or delocalized surface plasmon-polaritons has been studied in graphene nanostructures, we consider here the interaction between a localized and a delocalized surface plasmon-polariton. This interaction can be achieved by two different schemes that reside on either evanescent near-field coupling or far-field interference. All observable phenomena are corroborated by analytical considerations, providing insight into the physics and paving the way for compact and tunable optical components at infrared and terahertz frequencies.