Hybrid plasmonic graphene modulator with buried silicon waveguide

Abstract

We propose a low-loss broadband modulator by combining plasmonic effect with graphene to realize highly efficient modulation on the SOI (Silicon-On-Insulator) platform. Due to a hybrid plasmonic waveguide including buried silicon waveguide and silver waveguides, the fundamental mode is mainly confined in two single-layer graphene sheets, and the electric field vector is parallel to the graphene sheets ensuring the high efficient light absorption of graphene. The specific hybrid structure makes it easy for graphene transfer. Also, non-coplanar structure of silicon waveguide and silver waveguides provides simplified fabrication process and fabrication tolerance. The simulation results demonstrated that modulation bandwidth of 346 GHz is obtained, and the 3 dB modulation length is only 9.493μm. In addition, competitively low propagation loss of 0.85 dB was realized of the hybrid modulator.