Tunable metamaterial structures and slow light effects using plasmon induced transparency

We present a dynamically frequency tunable plasmon induced transparency(PIT) in metamaterial devices composed of a graphene nanostructure for the terahertz (1-10 THz) region. The most common way to get a PIT effect is creating the coupling between bright and dark modes. Graphene show unusual behavior that enables new tunable plasmonic metamaterials and applications in terahertz frequency range. The PIT resonant frequency can be dynamically tuned by varying the gate voltage applied to the graphene without re-fabrication the nanostructures. A metamaterial sensor based on these coupling effects yields a sensitivity of 8152 nm/RIU. PIT has been demonstrated to be able to greatly slow down the speed of light. Slow light is important for routing optical information. In the vicinity of the PIT transparent peak it offers a large positive group Index, suggesting slow light. At the transparent peak, the group Index is 278.7. These features show remarkable potential for slow light devices, optical sensing and switching in metamaterials.