Light & Matter Seminar: Professor Mikhail Vasilevskiy - Is graphene an extraordinary nonlinear optical material?

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Join Professor Mikhail Vasilevskiy from the University of Minho for a Light & Matter Seminar entitled 'Is graphene an extraordinary nonlinear optical material?

Abstract:

It was predicted about 15 years ago that graphene should have a strong nonlinear (NL) optical response in a broad spectral range [1]. This prediction, particularly interesting for the THz region, stimulated numerous theoretical and experimental studies. In 2014, a THz bistability of graphene was predicted [2], but experimental observations of this effect still seem to be lacking. Also in 2014, it was argued that the NL refractive index owing to interband transitions can become very large due to resonant enhancement, but so does the absorption coefficient, which makes graphene a rather ordinary NL material in the visible and infrared (IR) range [3]. Furthermore, there is a large dispersion of the literature data on the NL refractive index of graphene in the vis-IR [4]. On the other hand, an efficient high harmonic generation relative to the spectrum of the pumping field with 0.3 THz frequency was demonstrated recently [5].

In this talk I will try to answer the question posed in the title covering the following topics:

(i) NL response of graphene in the THz and far-IR range related to intraband electronic transitions and Drude-type surface plasmons (higher harmonic generation and bistability);

(ii) NL response of graphene in the vis-IR range under ultrafast optical pumping;

(iii) Generation of graphene surface plasmons by optical beams caused by frequency difference NL processes [6,7].

References:

[1] S.A. Mikhailov, Non-linear electromagnetic response of graphene, Europhys. Lett. 79 (2007) 27002

[2] N.M.R. Peres, Y.V. Bludov, J.E. Santos, A.-P. Jauho, M.I. Vasilevskiy, Optical bistability of graphene in the terahertz range, Phys. Rev. B 90 (2014) 125425

[3] J.B. Khurgin, Graphene – A rather ordinary nonlinear‐optical material, Appl. Phys. Lett. 104 (2014) 161116

[4] D. Castelló‐Lurbe, H. Thienpont, N. Vermeulen, Predicting Graphene's Nonlinear‐Optical Refractive Response for Propagating Pulses, Laser & Photonics Reviews 14 (2020) 1900402

[5] H.A. Hafez et al., Extremely efficient terahertz high-harmonic generation in graphene by hot Dirac fermions, Nature 561 (2018) 507

[6] T. Constant et al., All-optical generation of surface plasmons in graphene, Nature Physics 12 (2016) 124

[7] R. Dias, J.C. Viana Gomes, M.I. Vasilevskiy, Analysis of All-Optical Generation of Graphene Surface Plasmons by a Frequency-Difference Process", Appl. Sci. 12 (2022),12376