Ultra-broadband and tunable slow surface plasmon polaritions in a simple graphene-based waveguide

The strongly delayed wave with large bandwidth in a graphene-based grating waveguide has been reported previously. However, a clear slow wave performance in a simple graphene-based uniform waveguide has not been explored. Here, we analyzed for the first time a delayed surface wave in this waveguide. The strongly delayed wave with extremely large bandwidth can be dynamically controlled via the bias-voltage dependent optical properties of graphene. The simple waveguide is an excellent candidate for slow light applications because of easy fabrication, ultra-high slowdown factor, ultra-large bandwidth and conveniently tunable group velocity.