Multilayer graphene on hBN substrate waveguide modulator

A multilayer graphene-based optical modulator is proposed in this study. The structure is made of several layers of graphene on hexagonal boron nitride (hBN), working at 193 to 200 THz (1.5 to 1.55 mu m) band. In this modulator, the electric field passes through graphene layers instead of passing through the silicon waveguide, causing very low insertion losses about 4 x 10(-3) dB for 40 mu m long device. It is shown that the transverse magnetic mode has a more efficient propagation in the modulator. Due to the passage of light from graphene layers and the graphene's optical characteristics, light transmission can be controlled with less variation in gate voltage, and it has the better switching performance concerning monolayer, bilayer and diagonal graphene optical modulators.