Figure 3. Absorption enhancement in graphene by plasmonic light trapping with dual resonances.

(a) Simulated spectra of total absorption (blue dashed line) as well as absorption in the graphene (red solid line) for the structure in Fig. 1b. The light is incident at normal direction with its electric field polarized along the x-direction. (b,c) show the field distributions at the two resonances as denoted in (a) by the vertical dashed lines. The field is plotted at the x–y plane that is 25 nm below the bottom surface of the gold crosses. The flat dashed lines show the absorption in a free standing graphene without enhancement.