A new scheme to enhance the third-harmonic generation in graphene

In this paper, a new approach is proposed to efficiently enhance the third-harmonic generation (THG) in graphene by employing a bilayer-grating structure. This scheme relies on the fact that the optical resonances of graphene structures are determined by the geometry. To boost the THG, we optimize the geometry of graphene bilayer gratings, thus achieving more than eight orders of magnitude enhancement of the THG intensity.