Light amplitude modulation in photonic waveguides using graphene plasmonic resonance

Hybrid waveguides with graphene can enable resonant coupling of the waveguide mode and the graphene plasmonic modes. We demonstrate theoretically that the plasmonic resonance can be significantly enhanced using a graphene nanoribbon with a deep subwavelength width when a lower-order graphene nanoribbon mode and a mode of a bare waveguide are efficiently coupled. A further increase by order of magnitude is possible when a single graphene stripe is replaced by a finite array of graphene nanoribbons. This effect may provide a feasible platform for an efficient amplitude modulation which can be employed in design of specific devices such as low-power modulators, filters or sensors.