Enhanced four-wave mixing in graphene-integrated silicon slot waveguides

Abstract Leveraging graphene’s giant third-order nonlinearity and ultrafast response, we experimentally demonstrate a graphene-integrated slot waveguide designed to maximize the effective light–matter interaction. Through four-wave mixing experiments, we achieved a conversion efficiency of −29.1 dB in a slot waveguide covered with an optimized graphene-light interaction length of 60 μm, outperforming the slot waveguide structures by approximately 18.4 dB. This device not only provides pathways for realizing high-speed and low-power all-optical signal processing, but also lays a sound theoretical and experimental foundation for the design and integration of highly nonlinear silicon photonic devices.