Optical and Terahertz Energy Concentration on the Nanoscale in Plasmonics

We introduce an approach to implement full coherent control on nanometer length scales. It is based on spatiotemporal modulation of the surface plasmon polariton (SPP) fields at the thick edge of a nanowedge. The SPP wavepackets propagating toward the sharp edge of this nanowedge are compressed and adiabatically concentrated at a nanofocus, forming an ultrashort pulse of local fields. The profile of the focused waveform as a function of time and one spatial dimension is completely coherently controlled. We establish the principal limits for the nanoconcentration of the terahertz (THz) radiation in metal/dielectric waveguides and determine their optimum shapes required for this nanoconcentration. We predict that the adiabatic compression of THz radiation from the initial spot size of vacuum wavelength ~300 μm to the unprecedented final size of 100-250 nm can be achieved, while the THz radiation intensity is increased by a factor of 10 to 250. This THz energy nanoconcentration will not only improve the spatial resolution and increase the signal/noise ratio for THz imaging and spectroscopy, but in combination with the recently developed sources of powerful THz pulses, will allow the observation of nonlinear THz effects and a variety of nonlinear spectroscopies (such as two-dimensional spectroscopy), which are highly informative. This should find a wide spectrum of applications in science, engineering, biomedical research and environmental monitoring. We also develop a theory of the spoof plasmons propagating at the interface between a dielectric and a real conductor. The deviation from a perfect conductor is introduced through a finite skin depth. The possibilities of guiding and focusing of spoof plasmons are considered. Geometrical parameters of the structure are found which provide a good guiding of such modes. Moreover, the limit on the concentration by means of planar spoof plasmons in case of non-ideal metal is established. These properties of spoof plasmons are of great interest for THz technology

Transforming Fabry-Perot resonances into a Tamm mode

We propose a novel photonic structure composed of metal nanolayer, Bragg mirror and metal nanolayer. The structure supports resonances that are transitional between Fabry-Perot and Tamm modes. When the dielectric contrast of the DBR is removed these modes are a pair of conventional Fabry-Perot resonances. They spectrally merge into a Tamm mode at high contrast. Such behavior differs from the results for structures supporting Tamm modes reported earlier. The optical properties of the structure in the frequency range of the DBR stop band, including highly beneficial 50% transmittivity through thick structures, are determined by the introduced in the paper hybrid resonances. The results can find a wide range of photonic applications.Comment: 5 pages, 4 figure

Giant Surface Plasmon Induced Drag Effect (SPIDEr) in Metal Nanowires

Here, for the first time we predict a giant surface plasmon-induced drag effect (SPIDEr), which exists under conditions of the extreme nanoplasmonic confinement. Under realistic conditions, in nanowires, this giant SPIDEr generates rectified THz potential differences up to 10 V and extremely strong electric fields up to 10^5-10^6 V/cm. The SPIDEr is an ultrafast effect whose bandwidth for nanometric wires is 20 THz. The giant SPIDEr opens up a new field of ultraintense THz nanooptics with wide potential applications in nanotechnology and nanoscience, including microelectronics,nanoplasmonics, and biomedicine.Comment: 5 pages, 3 figure

Toward Full Spatio-Temporal Control on the Nanoscale

We introduce an approach to implement full coherent control on nanometer length scales. It is based on spatio-temporal modulation of the surface plasmon polariton (SPP) fields at the thick edge of a nanowedge. The SPP wavepackets propagating toward the sharp edge of this nanowedge are compressed and adiabatically concentrated at a nanofocus, forming an ultrashort pulse of local fields. The one-dimensional spatial profile and temporal waveform of this pulse are completely coherently controlled.Comment: 4 pages, 3 figures Figures were replace

Ultrafast Dynamic Metallization of Dielectric Nanofilms by Strong Single-Cycle Optical Fields

We predict a dynamic metallization effect where an ultrafast (single-cycle) optical pulse with a field less or on the order of 1 V/Angstrom causes plasmonic metal-like behavior of a dielectric film with a few-nm thickness. This manifests itself in plasmonic oscillations of polarization and a significant population of the conduction band evolving on a femtosecond time scale. These phenomena are due a combination of both adiabatic (reversible) and diabatic (for practical purposes irreversible) pathways.Comment: 4 pages, 4 figure

Predicted Ultrafast Dynamic Metallization of Dielectric Nanofilms by Strong Single-Cycle Optical Fields

We predict a dynamic metallization effect where an ultrafast (single-cycle) optical pulse with a ≲1  V/Åfield causes plasmonic metal-like behavior of a dielectric film with a few-nm thickness. This manifests itself in plasmonic oscillations of polarization and a significant population of the conduction band evolving on a ∼1  fs time scale. These phenomena are due to a combination of both adiabatic (reversible) and diabatic (for practical purposes irreversible) pathways

Transforming Fabry-Pérot Resonances into a Tamm Mode

We propose an optical structure composed of two metal nanolayers enclosing a distributed Bragg reflector (DBR) mirror. The structure is an open photonic system whose bound modes are coupled to external radiation. We apply the special theoretical treatment based on inversion symmetry of the structure to classify its resonances. We show that the structure supports resonances transitional between Fabry-Pérot modes and Tamm plasmons. When the dielectric contrast of the DBR is removed these modes are a pair of conventional Fabry-Pérot resonances. They spectrally merge into a Tamm mode at high contrast. The optical properties of the structure in the frequency range of the DBR stop band, including highly beneficial 50% transmittivity through thick structures with sub-skin-depth metal films, are determined by the hybrid quasinormal modes of the open nonconservative structure under consideration. The results can find a broad range of applications in photonics and optoelectronics, including the possibility of coherent control over optical fields in the class of structures similar to the one proposed here

Самостоятельная занятость как форма реинтеграции безработных граждан в социум

This article deals with one of the types of employment – self-employment, its importance for reintegration of unemployed people into society, showing the need for its development and management at the regional level; a conceptual model of management of self-employment, its main provisions, the algorithm of realization of the model are proposed; the subject and principles of management are shown.В статье рассмотрен один из видов занятости населения – самостоятельная занятость, ее значение для реинтеграции безработных людей в социум, показана необходимость ее развития и управления на уровне региона, предложена концептуальная модель управления самозанятостью, ее основные положения, алгоритм реализации модели, указаны предмет и принципы управления