▎ 摘　　要

A graphene layer interacting with an incident electromagnetic wave of frequency omega will produce dipole radiation at frequency 2 omega in the presence of an in-plane electric field breaking the spatial inversion symmetry of the graphene. Here, we develop a theory that describes such electric-field-induced second harmonic generation (EFISHG) from doped graphene. We derive an analytic expression for the relevant third-order nonlinear optical (NLO) susceptibility chi((3))(- 2 omega; omega, omega, 0) and numerically evaluate the absolute magnitude of the chi((3)) for various values of the system's parameters. We find that the vertical bar chi((3))vertical bar spectrum is dominated by the resonant peak structure located at the incident photon energy h omega equal to the Fermi energy E-F of charge carriers in the doped graphene. We also show that the possibility to tune the doping level of graphene by an external gate voltage allows one to maximize the radiated EFISHG power at h(omega) = E-F, which may be of practical interest for the designs of the NLO devices based on employing a SHG-signal. (C) 2016 Elsevier Ltd. All rights reserved.