Dynamic control of wideband slow wave in graphene based waveguides.

Enlarged group index has been reported previously when surface plasmons propagate through the graphene sheet, yet a clear slow wave performance in graphene has not been explored. We proposed and numerically analyzed here for the first time to the best of our knowledge an extremely wideband slow surface wave in a graphene-based grating waveguide. The strongly delayed wave (120<n(g)<167) with extremely large bandwidth (2.7 THz>Δf>0.7 THz) can be dynamically controlled via the gate-voltage dependent optical properties of graphene. Our results suggest that graphene may be a very promising slow light medium, promoting future slow light devices based on graphene.