High Extinction Ratio Hybrid Graphene-Silicon Photonic Crystal Switch

In this letter, we demonstrate a compact optical switch realized by integrating a graphene layer with a silicon photonic crystal cavity fabricated using deep UV immersion lithography and a novel transfer printing approach. A 17-dB extinction ratio and 0.75-nm shift in the cavity resonance are measured for a swing voltage of only 1.2 V. The graphene layer is limited to 1 × 5 μm in size. The experimental results are linked to a theoretical model and used to predict possible improvements to the design.