Ultracompact optical modulator based on graphene-silica metamaterial.

We present an ultracompact electro-optic modulator with a length of 15 nm by utilizing a permittivity-tunable metamaterial channel, which is composed of alternative layers of graphene and silica. Optical waves can propagate through the metamaterial channel only if its permittivity is tuned to be near zero. The finite-difference time-domain (FDTD) simulations show the insertion loss is roughly -0.27  dB while the 3 dB extinction ratio is obtained with a 0.8 V gate voltage. The device's footprint is as small as 0.01 μm2. This modulator consumes low power and can potentially be ultrafast.