Fig. 3From: Plasmonically induced perfect absorption in graphene/metal systemThe optical response varies with the coupling distance. a The reflection. b Absorption spectra of the structure of graphene-silver groove in normal incidence for different distance g between the graphene and the silver groove. The black curve/the blue balls are calculated by FDTD method and the red curve is analytical fit by Eq. (3) of the PIA deviceBack to article page