Rabi Oscillations of Plasmonic Supermodes in Graphene Multilayer Arrays

We investigate Rabi oscillations of surface plasmon polaritons in the graphene waveguide array consisting of spatially separated graphene multilayers in each period. The plasmonic supermodes generated in the graphene multilayers of each period should couple to each other, yielding Bloch modes in the graphene multilayer array (GMA). By introducing spatial modulation of dielectric permittivity between graphene, both direct and indirect transitions may occur, resulting in the cross conversion of both co- and counter-propagating Bloch modes in different bands. As the number of supermodes depends on that of graphene layers in each period of the GMA, there should be multiple bands for the plasmonic Bloch modes. Thus, the transition could occur between the modes in any distinct bands. The study may find great applications in graphene-based mode converters, switches, and modulators.