Proposal for a 2$\,\times\,$2 Optical Switch Based on Graphene-Silicon-Waveguide Microring

We propose a new method to change the resonant status of the microring by modifying the light-absorption ability of the waveguide. A conception of a 2 × 2 microring switch based on the graphene-silicon-waveguide is presented by inserting a single graphene flake inside the lateral slot waveguide. The resonance procedure of the microring is thoroughly blocked when the graphene is tuned to be a zero-permittivity material, which significantly enhances the waveguide's loss. Neither a high quality factor nor a large driving voltage of the microring is needed. According to the numerical analysis, an extinction ratio for is obtained in the drop port with a broad bandwidth. The extinction ratio in the through port is 34 dB. The radius of the microring is 5.1 μm and the driving voltage is 2.38 V.