Modulation of mid-infrared light using graphene-metal plasmonic antennas

We show that large modulation of the amplitude and phase of mid-infrared light can be achieved by dynamically shifting the resonance of graphene-metal plasmonic antennas via electrical tuning of the optical conductivity of graphene. Intensity modulation with on-off extinction ratio exceeding 100 and phase modulation over a range of 240° are demonstrated by simulations of scattered light from arrays of such antennas. The modulation rate is estimated to be on the order of a few GHz. These properties are promising for creating reconfigurable flat optical components such as spatial light modulators in the mid-infrared spectral range.