  Efficient conversion of electrical signal to optical signal in nano-photonics
enables solid state integration of electronics and photonics. Combination of
graphene with photonic crystals is promising for electro-optic modulation. In
this paper, we demonstrate that by electrostatic gating a single layer of
graphene on top of a photonic crystal cavity, the cavity resonance can be
changed significantly. A ~2nm change in the cavity resonance linewidth and
almost 400% (6 dB) change in resonance reflectivity is observed. In addition,
our analysis shows that a graphene-photonic crystal device can potentially be
useful for a high speed, and low power absorptive and refractive modulator,
while maintaining a small physical footprint.
