Electrically tunable third-order nonlinear optical response in graphene

The research focus on 2-D materials has intensified with its potential to modulate light for superior performance and realize applications that can enhance existing technologies. Graphene, the best known 2-D material, derived from 3-D graphite, constitutes a monolayer of carbon atoms arranged in a 2-D hexagonal lattice, exhibiting strong ultra-wideband light-matter interactions, able to operate at an extremely broad spectral range, suited for next-generation photonics and optoelectronic devices. The unique electronic properties of graphene originate from Dirac cones, features in electronic band structures that host charge carriers of zero effective mass, so-called massless Dirac fermions that occur in 2-D materials. Materials scientists are currently at a stage of experimental infancy to realize many interesting properties of the nonlinear optical responses of graphene, to aid its promise to disrupt existing technology and facilitate wide-ranging applications.