Metals support surface plasmons at optical wavelengths and have the ability to localize light subwavelength regions. The field enhancements that occur in these regions set ultimate limitations on a wide range of nonlinear quantum phenomena. We found dominant limiting factor is not resistive loss metal, but rather intrinsic nonlocality its dielectric response. A semiclassical model electronic response metal places strict bounds enhancement. To demonstrate accuracy this model, we studied...

We push the fabrication limit of gold nanostructures to exciting sub-nanometer regime, in which light–matter interactions have been anticipated be strongly affected by quantum nature electrons metals. Doing so allows us (1) evaluate validity classical electrodynamics describe plasmonic effects at this length scale and (2) witness gradual (instead sudden) evolution plasmon modes when two nanoprisms are brought into contact. Using electron energy-loss spectroscopy transmission microscope...

On the basis of conformal transformation, a general strategy is proposed to design plasmonic nanostructures capable an efficient harvesting light over broadband spectrum. The surface plasmon modes propagate toward singularity these structures where group velocity vanishes and energy accumulates. A considerable field enhancement confinement thus expected. Radiation losses are also investigated when structure dimension becomes comparable wavelength.

We demonstrate the use of high-resolution electron beam lithography to fabricate complex nanocavities with nanometric spatial and positional control. The plasmon modes these nanostructures are then mapped using energy-loss spectroscopy in a scanning transmission microsope. This powerful combination patterning mapping provides direct experimental verification theoretical predictions hybridization theory metal allows determination full mode spectrum such cavities.

Surface plasmons on metals can concentrate light into subnanometric volumes and these near atomic length scales the electronic response at metal interface is smeared out over a Thomas-Fermi screening length. This nonlocality barrier to good understanding of scale complicates practical matter computing fields. In this Letter, we present local analogue model show that spatial be represented by replacing nonlocal with composite material, comprising thin dielectric layer top metal. method not...

Metallic nanostructures provide a toolkit for the generation of coherent light below diffraction limit. Plasmonic based lasing relies on population inversion emitters (such as organic fluorophores) along with feedback provided by plasmonic resonances. In this regime, known weak matter coupling, radiative characteristics system can be described Purcell effect. Strong coupling between molecular excitons and electromagnetic field generated structures leads to formation hybrid quasi-particles...

We develop an insightful transformation-optics approach to investigate the impact that nonlocality has on optical properties of plasmonic nanostructures. The light-harvesting performance a dimer touching nanowires is studied by using hydrodynamical Drude model, which reveals nonlocal resonances not predicted previous local calculations. Our method clarifies interplay between radiative and effects in this nanoparticle configuration, enables us elucidate optimum size maximizes its absorption...

Structuring metallic surfaces allows for the support of surface electromagnetic modes at frequencies which they would not be allowed smooth surfaces. These are called ``spoof plasmons'' because their similarity to plasmons that supported optical This article describes physics underlies behavior spoof and how these used in applications require manipulation fields below optical.

A new approach for the spatial and temporal modulation of electromagnetic fields at terahertz frequencies is presented. The waveguiding elements are based on plasmonic metamaterial notions consist an easy-to-manufacture periodic chain metallic box-shaped protruding out a surface. It shown that dispersion relation corresponding modes rather insensitive to waveguide width, preserving tight confinement reasonable absorption loss even when transverse dimensions well in subwavelength regime. This...

Polarization-controlled excitation of plasmonic modes in nanometric Au particle-on-film gaps is investigated experimentally using single-particle dark-field spectroscopy. Two distinct geometries are explored: nanospheres on top and inserted a thin gold film. Numerical simulations reveal that the three resonances arising scattering spectra measured for particles film originate from highly confined gap at interface. These feature different azimuthal characteristics, which consistent with...

Spoof plasmon surfaces consisting of linear arrays subwavelength grooves are proposed as a novel platform for THz sensing. The tightly confined spoof plasmons, coupled via an Otto prism setup, sensitive to the refractive index dielectric filling grooves. Phase jumps at resonances used readout response An overall sensitivity 0.49 RIU−1 with figures-of-merit high 49 achieved.

Nanoplasmonics is the emerging research field that studies light-matter interactions mediated by resonant excitations of surface plasmons in metallic nanostructures. It allows manipulation flow light and its interaction with matter at nanoscale (10(-9) m). One most promising characteristics plasmonic resonances they occur frequencies corresponding to typical electronic matter. This leads appearance strong between localized emitters (such as molecules, dyes, or quantum dots) placed vicinity...

Abstract A novel hybrid planar lens is proposed to engineer the far-field focusing patterns. It consists of an array slits which are filled with phase-change material Ge 2 Sb Te 5 (GST). By varying crystallization level GST from 0% 90%, Fabry-Pérot resonance supported inside each slit can be spectrally shifted across working wavelength at 1.55 µm, results in a transmitted electromagnetic phase modulation as large 0.56π. Based on this geometrically fixed platform, different fronts constructed...

The nanofocusing performance of plasmonic tips is studied analytically and numerically. effects electron-electron interactions in the dielectric response metal are taken into account through implementation a nonlocal, spatially dispersive, hydrodynamic permittivity. We demonstrate that spatial dispersion only slightly modifies device parameters which maximize its field enhancement capabilities. interplay between nonlocality, tip bluntness, surface roughness explored. show that, although...

Abstract We theoretically demonstrated and experimentally verified high-order radial spoof localized surface plasmon resonances supported by textured metal particles. Through an effective medium theory exact numerical simulations, we show the emergence of these geometrically-originated electromagnetic modes at microwave frequencies. The occurrence is in ultrathin disks. Their spectral near-field properties are characterized experimentally, showing excellent agreement with theoretical...

Transition metal dichalcogenides (TMDs) are layered semiconductors with indirect band gaps comparable to Si. These compounds can be grown in large area, while their gap(s) tuned by changing chemical composition or applying a gate voltage. The experimental evidence collected so far points toward strong interaction light, which contrasts the small photovoltaic efficiencies η ≤ 1% extracted from bulk crystals exfoliated monolayers. Here, we evaluate potential of these studying response...

In this paper, we show that broadband spectral data can be experimentally extracted from corrugated metallic surfaces consisting of a linear array subwavelength grooves supporting tightly confined spoof plasmons. Using combination the scattering edge coupling method and short-time Fourier transform, are able to discern group velocity characteristics plasmon pulse, which in turn allows for extraction dispersion 0.4 1.44 THz single measurement. Refractive index sensing various fluids is...

We investigate the conditions yielding plasmon-exciton strong coupling at single emitter level in gap between two metal nanoparticles. Inspired by transformation optics ideas, a quasianalytical approach is developed that makes possible thorough exploration of this hybrid system incorporating full richness its plasmonic spectrum. This allows us to reveal placing away from cavity center, multipolar dark modes both even and odd parity increases remarkably. way, reversible dynamics population...

We develop a framework that provides few-mode master equation description of the interaction between single quantum emitter and an arbitrary electromagnetic environment. The field quantization requires only fitting spectral density, obtained through classical simulations, to model system involving small number lossy interacting modes. illustrate power validity our approach by describing population electric spatial dynamics in spontaneous decay placed complex hybrid plasmonic-photonic structure.

Rooted in quantum optics and benefiting from its well-established foundations, strong coupling nanophotonics has experienced increasing popularity recent years. With being an experiment-driven field, the absence of appropriate theoretical methods to describe ground-breaking advances often emerged as important issue. To address this problem, temptation directly transfer extend concepts already available is strong, even if a rigorous justification not always available. In review we discuss...

Bound-states-in-the-continuum (BIC) is an emerging concept in nanophotonics with potential impact applications, such as hyperspectral imaging, mirror-less lasing, and nonlinear harmonic generation. As true BIC modes are non-radiative, they cannot be excited by using propagating light to investigate their optical characteristics. In this paper, for the 1st time, we map out strong near-field localization of resonance on arrays silicon nanoantennas, via electron energy loss spectroscopy a...