LAUSR

Abstract This paper presents a comprehensive study of light trapping and localization in graphene grating-sheet structure by numerical simulation, and shows a strategy to realize controllable absorption enhancement and localized field enhancement in a large-area continuous graphene monolayer. For the structure with strong plasmons coupling, more than 95% of total absorption and 60% of optical absorption in graphene sheet are realized at two different infrared wavelengths over a wide incident angle range. Meanwhile, the enhanced E-field around the graphene sheet is over 40 times of magnitude stronger than that of the incident field. Additionally, by changing the Fermi energy of graphene or the distance between the sheet and the grating, adjustable light trapping and switchable infrared absorber/reflector can be obtained. These features enable the coupled graphene grating-sheet to serve as platform for infrared sensing, photodetection and light-matter interactions.