Mid-infrared optical near-field switching in heterogeneous graphene ribbon pairs

The spatial switching of mid-infrared light near-fields is proposed in coupled graphene heterogeneous ribbon pairs. By using the coupled plasmon modes in graphene ribbon pairs, the electric near-field enhancement can be spatially controlled in graphene ribbons as the tuning of the external bias voltage difference. More specifically, due to symmetry breaking, the anti-symmetrically coupled dipolar plasmons exist except for the symmetrically coupled modes in homogeneous graphene pairs. Moreover, the gap distance is one of the key parameters for switching of electric near-fields, strong coupling means the efficient control of near-fields. (C) 2013 AIP Publishing LLC.