Plasmonic modulator utilizing graphene-HfO2-ITO stack embedded in the silicon waveguide

Abstract

In this paper, a compact, high extinction ratio, and low power consumption plasmonic modulator is designed by active materials of Indium Tin Oxide (ITO) and graphene. The proposed modulator consists of a Graphene/HfO2/ITO/HfO2/Graphene stack embedded in a silicon waveguide. Due to the simultaneous use of the Epsilon-Near-Zero property for both ITO and graphene, the maximum optical mode attenuation is obtained. Simulation results by Finite-Element-Method (FEM) show the high extinction ratio of 14.6 dB and insertion loss of 2.98 dB at a telecommunication wavelength of 1.55μm, while the energy consumption of 1.51 fj/bit is obtained for a unit length of 1 μm, which is the lowest in comparison to the previous works. Owing to the low power consumption and compact size of the proposed plasmonic modulator, it is useful for integrated photonics circuit and optic communications.