Harmonics generation, saturable absorption and other nonlinear phenomena in graphene

The discovery of graphene opened a new era in material science: the era of two-dimensional materials. These new materials have different properties: among them there are semiconductors like MoS₂, dielectrics like BN, and semimetals like graphene. In this paper we discuss what are the most important electronic properties of graphene and which kinds of electronic and optoelectronic applications they are most suitable for. We show that the linear energy dispersion of graphene electrons leads to a strongly nonlinear electrodynamic response of this material and overview a number of theoretically predicted and experimentally observed nonlinear electrodynamic phenomena in graphene, such as harmonics generation, frequency mixing, saturable absorption, etc.