Graphene plasmonics: All eyes on flatland

Light is difficult to control, particularly below the spatial scale set by the wavelength. Overcoming the diffraction limit of light will be crucial for combining nanoelectronics and optoelectronic devices. This convergence between electronics and photonics also opens up the question of how to efficiently modulate light propagation by electrical means. Two groups, writing in Nature, now show how graphene can be just such a light-guiding medium. Infrared electromagnetic radiation is funnelled into a strongly confined surface wave sustained on top of the graphene, where a gate voltage controls its transport. Taken together with its excellent electrical characteristics, this work opens up new possibilities for using graphene as the backbone of optoelectronic devices, with applications as diverse as light harvesting, photodetectors and optical sensing.