Surface plasmons in graphene have been widely studied
in the past decade due to their very appealing properties, such as
the strong tunability of its optical properties through electrical
gating and the relatively high plasmon lifetime. However, these
exceptional properties are limited to lower frequencies ranging
from the mid-infrared (mid-IR) to the terahertz (THz) spectral
regions. Additionally, electrical tunability of graphene cannot be
achieved in an ultrafast manner, what poses an obstacle for its
application in high-speed technological devices that are becoming
increasingly important.
