Optical second harmonic generation from nanostructured graphene: a full wave approach

Abstract

Optical second harmonic generation (SHG) from nanostructured graphene has been studied in the framework of classical electromagnetism using a surface integral equation method. Single disks and dimers are considered, demonstrating that the nonlinear conversion is enhanced when a localized surface plasmon resonance is excited at either the fundamental or second harmonic frequency. The proposed approach, beyond the electric dipole approximation used in the quantum description, reveals that SHG from graphene nanostructures with centrosymmetric shapes is possible when retardation effects and the excitation of high plasmonic modes at the second harmonic frequency are taken into account. Several SHG effects similar to those arising in metallic nanostructures, such as the silencing of the nonlinear emission and the design of double resonant nanostructures, are also reported. Finally, it is shown that the SHG from graphene disk dimers is very sensitive to a relative vertical displacement of the disks, opening new possibilities for the design of nonlinear plasmonic nanorulers.

Nonlinear Optics with 2D Layered Materials

“…However, SHG has been observed from the interface in different hybrid graphene devices regardless of the inversion symmetry in graphene. [61,62] Furthermore, the inversion symmetry can be broken by physical (e.g., structural engineering, [63,64] external electric field, [65] and multilayer structures [65][66][67] ) or chemical methods (e.g., chemical doping or etching [68] ). Very recently, electrically tunable THG and FWM in graphene have also been demonstrated.…”

An Insightful Picture of Nonlinear Photonics in 2D Materials and their Applications: Recent Advances and Future Prospects

“…Reproduced with permission. [ 267 ] Copyright 2016, The Authors, published by Wiley‐VCH. c) (i, ii) Monolayer, bilayer, trilayer and bulk phosphorene optical absorption spectra on behalf of incident light polarized along x direction.…”

“…These also show the presence of the Dirac point and energy band structure. [ 265 ] Diverse hybrid graphene accessories shows SHG irrespective of graphene inversion symmetry [ 27,28 ] and this inversion symmetry has been destroyed by using physical approaches, for example, structural engineering, [ 266,267 ] external electric field [ 38 ] and multilayer structures [ 38,268 ] or chemical methods. [ 68 ] In recent times, electrically variable graphene THG and FWM have been revealed.…”

Gate-Tunable Optical Nonlinearities and Extinction in Graphene/LaAlO3/SrTiO3 Nanostructures

“…The strong ~10 8 V/m localized electric field across the G/LAO/STO nanostructure may also lead one to consider nonlinear plasmonic processes, such as multi-plasmon absorption, as discussed by Jablan and Chang 36 . Since we observe a strong enhancement of the optical nonlinearity of the G/LAO/STO nanostructure, we also must take into account graphene's large intrinsic optical nonlinearities [37][38][39][40][41] .…”

“…These sharp extinction lines occur alongside a notably strong enhancement of optical rectification and second harmonic generation in the nanostructure. The G/LAO/STO nanostructure exhibits behavior reminiscent of doped graphene nanoribbon-, nanoisland-, or nanodisk-like structures 35,39,45,46 . In addition to its fundamental significance, this gate-tunable tunable enhanced light-matter interaction promises to strengthen graphene as a candidate material for nanophotonics and quantum optics applications.…”