▎ 摘　　要

We propose a structure of graphene embedded in dielectric resonant waveguide gratings to enhance the nonlinear interactions in graphene. Third harmonic generation (THG) from graphene is significantly enhanced in the waveguide mode under transverse electric polarization. Compared with the graphene on a flat dielectric film, the enhancement factor is up to 10(9). We in detail studied the THG intensity influenced by the Fermi level of graphene, the position of graphene, and multimode of waveguide. Our investigation has great significance for design and experimental fabrication of graphene-based nonlinear photonic devices.