Soavi, Giancarlo and Wang, Gang and Rostami, Habib and Purdie, David G. and De Fazio, Domenico and Ma, Teng and Luo, Birong and Wang, Junjia and Ott, Anna K. and Yoon, Duhee and Bourelle, Sean A. and Muench, Jakob E. and Goykhman, Ilya and Dal Conte, Stefano and Celebrano, Michele and Tomadin, Andrea and Polini, Marco and Cerullo, Giulio and Ferrari, Andrea C. (2018) Broadband, electrically tuneable, third harmonic generation in graphene. Nature Nanotechnology, 13. pp. 583-589. ISSN 1748-3387
Full text not available from this repository.Abstract
Optical harmonic generation occurs when high intensity light (>1010 W m–2) interacts with a nonlinear material. Electrical control of the nonlinear optical response enables applications such as gate-tunable switches and frequency converters. Graphene displays exceptionally strong light–matter interaction and electrically and broadband tunable third-order nonlinear susceptibility. Here, we show that the third-harmonic generation efficiency in graphene can be increased by almost two orders of magnitude by controlling the Fermi energy and the incident photon energy. This enhancement is due to logarithmic resonances in the imaginary part of the nonlinear conductivity arising from resonant multiphoton transitions. Thanks to the linear dispersion of the massless Dirac fermions, gate controllable third-harmonic enhancement can be achieved over an ultrabroad bandwidth, paving the way for electrically tunable broadband frequency converters for applications in optical communications and signal processing.