Complete complex amplitude modulation with graphene plasmonic active metamolecules

Abstract

Active metasurfaces have received remarkable attention due to the advantage of adjusting their functions without changing physical structures. However, the previous active metasurfaces suffer from an inevitable correlation between amplitude and phase modulation of light. They inherently lack the degrees of freedom to independently control the amplitude and phase of light due to their single resonant design. We introduce a metamolecule which incorporates two consecutive graphene plasmonic nano-resonators. The metasurface using active metamolecules can be free from correlation problems and independently control the amplitude and phase of the scattered wave. A generalized graphical approach has been developed for an intuitive design guideline. Furthermore, dynamic beam steering and holographic wavefront reconstruction are demonstrated by full-wave simulation.