Graphene-based plasmonic phase modulator for Terahertz-band communication

In this paper, a graphene-based plasmonic phase modulator for Terahertz band (0.1-10 THz) communication is proposed, modeled and analyzed. The modulator is based on a fixed-length graphene-based plasmonic waveguide, and leverages the possibility to tune the propagation speed of Surface Plasmon Polariton (SPP) waves on graphene by modifying the Fermi energy of the graphene layer. An analytical model for the modulator is developed starting from the dynamic complex conductivity of graphene and a revised dispersion equation for SPP waves in gated graphene structures. By utilizing the model, the performance of the modulator is analyzed in terms of symbol error rate when utilized to implement a M-ary digital phase shift keying modulation. The model is validated by means of electromagnetic simulations, and numerical results are provided to illustrate the performance of the modulator.