Scientists from ICFO, MIT, CNRS, CNISM and Graphenea collaborated to demonstrate how graphene can enable the electrical control of light at the nanometer level. Electrically controlled modulation of light emission is crucial in applications like sensors, displays and various optical communication system. It also opens the door to nanophotonics and plasmonics-based devices.
The researchers managed to show that the energy flow from erbium into photons or plasmons can be controlled by applying a small electrical voltage. The plasmons in graphene are unique, as they are very strongly confined, with a plasmon wavelength that is much smaller than the wavelength of the emitted photons. As the Fermi energy of the graphene sheet was gradually increased, the erbium emitters went from exciting electrons in the graphene sheet, to emitting photons or plasmons. The experiments showed the graphene plasmons at near-infrared frequencies, which may be beneficial for communications applications. In addition, the strong concentration of optical energy offers new possibilities for data storage and manipulation through active plasmonic networks.
This research was partially funded by the EC Graphene Flagship.