▎ 摘　　要

In this paper, we propose and theoretically investigate a silicon-based hybrid nonlinear photonic device with a silicon nitride (Si3N4) film sandwiched between a graphene sheet and a silicon photonic crystal waveguide (PCW). With properly designed structural parameters of the silicon PCW and the presence of Si3N4 buffer layer, enhanced interaction between the optical field and graphene can be achieved to improve four-wave mixing (FWM) process in the device. The influences of the silicon PCW and the Si3N4 buffer layer thicknesses on FWM conversion efficiency are also analyzed. Numerical simulation results show that up to 19.66 dB improvement of the FWM conversion efficiency can be obtained in the proposed device. (C) 2015 Optical Society of America