%N 2090 %J Philosophical Transactions of the Royal Society A - Mathematical Physical and Engineering Sciences %V 375 %A JW You %A J You %A M Weismann %A NC Panoiu %K graphene, plasmons, third-harmonic generation %X Intriguing and unusual physical properties of graphene offer remarkable potential for advanced, photonics-related technological applications, particularly in the area of nonlinear optics at the deep-subwavelength scale. In this study, we use a recently developed numerical method to illustrate an efficient mechanism that can lead to orders of magnitude enhancement of the third-harmonic generation in graphene diffraction gratings. In particular, we demonstrate that by taking advantage of the geometry dependence of the resonance wavelength of localized surface-plasmon polaritons of graphene ribbons and discs one can engineer the spectral response of graphene gratings so that strong plasmonic resonances exist at both the fundamental frequency and third-harmonic (TH). As a result of this double-resonant mechanism for optical near-field enhancement, the intensity of the TH can be increased by more than six orders of magnitude. %T Double-resonant enhancement of third-harmonic generation in graphene nanostructures %O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. %D 2017 %I ROYAL SOC %L discovery1549534