Graphene has shown great promise in upcoming plasmonic future where photons can be electrically controlled. However, this requires designing appropriate photonic materials where graphene can be used an active material. 
In a recent report in Nature Materials, it is indeed demonstrated that graphene, in conjunction with the metamaterial, can modulate both the amplitude and phase of the transmitted waves.

http://www.nature.com/nmat/journal/v11/n11/full/nmat3433.html?WT.ec_id=NMAT-201211