Turning graphene into light nanosensors (Vol. 49 No.5-6)

Absorption on the plane of incident angle and wavelength

Tuning the graphene embedded in a photonic crystal by varying the external temperature can transform it into a light-sensitive sensor

Graphene has many properties; it is e.g. an extremely good conductor. But it does not absorb light very well. To remedy this limiting aspect of what is an otherwise amazing material, physicists resort to embedding a sheet of graphene in a flat photonic crystal, which is excellent for controlling the flow of light. The combination endows graphene with substantially enhanced light-absorbing capabilities. In a new study published recently, the authors demonstrate that, by altering the temperature in such a hybrid cavity structure, they can tune its capacity for optical absorption. They explain that it is the thermal expansion and thermo-optical effects which give the graphene these optical characteristics. Potential applications include light sensors, ultra-fast lasers, and systems capable of modulating incoming optical beams.

A. Rashidi and A. Namdar, Tunability of temperature-dependent absorption in a graphene-based hybrid nanostructure cavity, Eur. Phys. J. B 91, 68 (2018)