▎ 摘　　要

The tunable absorption effects with cascaded graphene nanoribbon arrays are investigated. It is achieved by cascading two pairs of graphene nanoribbon arrays-dielectric spacers on a metallic mirror. It is found that dual-band and a broadband absorbers can be easily achieved by tuning the geometry parameters of the structure. The designed dual-band graphene absorber exhibits near-unity absorption at two resonant frequencies and the broadband absorber shows high absorption over a wide frequencies range. Moreover, the absorption performance can not only be tuned in wide frequency ranges by changing the Fermi level, but also be maintained over a large incident angle range. It is believed that the concepts can be expanded to design multiband and more broadband absorbers by cascading many pairs of graphene nanoribbon arrays-dielectric spacers. (C) 2019 Society of Photo-Optical Instrumentation Engineers (SPIE)