Related papers: Harmonic generation from gold nanolayers: an old p…
The enhancement and control of non-linear phenomena at a nanometer scale has a wide range of applications in science and in industry. Among these phenomena, high-harmonic generation in solids is a recent focus of research to realize next…
Second harmonic generation (SHG) is forbidden from most bulk metals, because metals are characterized by a net zero electric-field in equilibrium. This limit breaks down when reaching nanoscale dimensions, as have been shown for metallic…
Monolayer transition metal dichalcogenides (TMDs) exhibit high nonlinear optical (NLO) susceptibilities. Experiments on MoS$_2$ have indeed revealed very large second-order ($\chi^{(2)}$) and third-order ($\chi^{(3)}$) optical…
Nonlinear second harmonic optical activity of graphene covering a gold photon sieve was determined for different polarizations. The photon sieve consists of a subwavelength gold nanohole array placed on glass. It combines the benefits of…
We study second and third harmonic generation in centrosymmetric semiconductors at visible and UV wavelengths in bulk and cavity environments. Second harmonic generation is due to a combination of symmetry breaking, the magnetic portion of…
Due to its linear dispersion, monolayer graphene is expected to generate a third harmonic response at terahertz frequencies. There have been a variety of different models of this effect and recently it has been experimentally observed.…
We present a semiclassical model for plasmon-enhanced high-harmonic generation (HHG) in the vicinity of metal nanostructures. We show that both the inhomogeneity of the enhanced local fields and electron absorption by the metal surface play…
The applications of plasmonics to energy transfer from free-space radiation to molecules are currently limited to the visible region of the electromagnetic spectrum due to the intrinsic optical properties of bulk noble metals that support…
Second-order nonlinear optical processes do not manifest in the bulk of centrosymmetric materials, but may occur in the angstroms-thick layer at surfaces. At such length-scales, quantum mechanical effects come into play which could be…
We demonstrated nonperturbative high harmonics induced by intense mid-infrared light up to 18th order that well exceed the material bandgap in monolayer transition metal dichalcogenides. The intensities of the even-order high-harmonic…
We present experimental and theoretical results for the angular dependence of third harmonic generation (THG) of water droplets in the micrometer range (size parameter $62<ka<248$). The THG signal in $p$- and $s$-polarization obtained with…
In this article, we develop a classical electrodynamic theory to study the optical nonlinearities of metallic nanoparticles. The quasi-free electrons inside the metal are approximated as a classical Coulomb-interacting electron gas, and…
We present a combined experimental and theoretical study of enhanced third-harmonic generation (THG) in silicon nitride metasurfaces. These structures exhibit strong resonant nonlinear responses, enabling up to two orders of magnitude…
We observe optical third harmonic generation from graphene and few-layer graphite flakes produced by exfoliation. The emission scales with the cube of the intensity of the incident near-infrared femtosecond pulses and has a wavelength that…
We study the enhancement of third harmonic generation in indium tin oxide nanolayers coupled to Tamm plasmon polaritons (TPPs). The TPPs are excited at the interface between a thin gold mirror and a silicon dioxide/silicon nitride…
In the framework of time-dependent density functional theory, we obtain high-order harmonics of photon energies up to 10 Up from bilayer crystals with an interlayer spacing d = 70 {\AA}. At grazing incidence, a clear double-plateau…
Whispering-gallery-mode microcavities are known to have high optical quality factor, making them suitable for nonlinear optical interactions. Here, third-harmonic generation is observed using a relatively small radius wedge silicon oxide…
Noble-metal nanoparticles for photocatalysis have become a major research object in recent years due to their plasmon-enhanced strong light-matter interaction. The dynamics of the hot electrons in the noble metal are crucial for the…
We show that second harmonic generation can be enhanced by Fano resonant coupling of asymmetric plasmonic metal nanostructures. We develop a theoretical model examining the effects of electromagnetic interaction between two metal…
The search for miniaturized components for nonlinear optical processes needs a way to overcome the efficiency loss due to the effective size reduction of the active medium. We investigate here a combination of a nanosized nonlinear…