Near-infrared electro-optic modulator based on plasmonic graphene.

We propose a novel scheme for an electro-optic modulator based on plasmonically enhanced graphene. As opposed to previously reported designs where the switchable absorption of graphene itself was employed for modulation, here a graphene monolayer is used to actively tune the plasmonic resonance condition through the modification of interaction between optical field and an indium tin oxide (ITO) plasmonic structure. Strong plasmonic resonance in the near infrared wavelength region can be supported by accurate design of ITO structures, and tuning the graphene chemical potential through electrical gating switches on and off the ITO plasmonic resonance. This provides much increased electro-absorption efficiency as compared to systems relying only on the tunable absorption of the graphene.