506 research outputs found
Giant In-Particle Field Concentration and Fano Resonances at Light Scattering by High-Refractive Index Particles
A detailed analytical inspection of light scattering by a particle with high
refractive index m+i\kappa and small dissipative constant \kappa is presented.
We have shown that there is a dramatic difference in the behavior of the
electromagnetic field within the particle (inner problem) and the scattered
field outside it (outer problem). With an increase in m at fix values of the
other parameters, the field within the particle asymptotically converges to a
periodic function of m. The electric and magnetic type Mie resonances of
different orders overlap substantially. It may lead to a giant concentration of
the electromagnetic energy within the particle. At the same time, we
demonstrate that identical transformations of the solution for the outer
problem allow to present each partial scattered wave as a sum of two
partitions. One of them corresponds to the m-independent wave, scattered by a
perfectly reflecting particle and plays the role of a background, while the
other is associated with the excitation of a sharply-m-dependent resonant Mie
mode. The interference of the partitions brings about a typical asymmetric Fano
profile. The explicit expressions for the parameters of the Fano profile have
been obtained "from the first principles" without any additional assumptions
and/or fitting. In contrast to the inner problem, at an increase in m the
resonant modes of the outer problem die out, and the scattered field converges
to the universal, m-independent profile of the perfectly reflecting sphere.
Numerical estimates of the discussed effects for a gallium phosphide particle
are presented.Comment: 18 pages, 10 figure
Radiation Pressure Quantization
Kepler's observation of comets tails initiated the research on the radiation
pressure of celestial objects and 250 years later they found new incarnation
after the Maxwell's equations were formulated to describe a plethora of
light-matter coupling phenomena. Further, quantum mechanics gave birth to the
photon drag effect. Here, we predict a novel universal phenomenon which can be
referred to as quantization of the radiation pressure. We develop a microscopic
theory of this effect which can be applied to a general system containing
Bose-Einstein-condensed particles, which possess an internal structure of
quantum states. By analyzing the response of the system to an external
electromagnetic field we find that such drag results in a flux of particles
constituting both the condensate and the excited states. We show that in the
presence of the condensed phase, the response of the system becomes quantized
which manifests itself in a step-like behavior of the particle flux as a
function of electromagnetic field frequency with the elementary quantum
determined by the internal energy structure of the particles.Comment: Manuscript: 4 pages, 3 figure
Fano resonance in quadratic waveguide arrays
We study resonant light scattering in arrays of channel optical waveguides
where tunable quadratic nonlinearity is introduced as nonlinear defects by
periodic poling of single (or several) waveguides in the array. We describe
novel features of wave scattering that can be observed in this structure and
show that it is a good candidate for the first observation of Fano resonance in
nonlinear optics.Comment: 3 pages, 3 figures, submitted to Optics Letters, slightly revise
Housing conditions of the population of cities of the Urals in the 1920s and the first half of the 1930s.
В статье охарактеризованы условия проживания в «городках ОГПУ», домах-коммунах, общежитиях, бараках, особенности организации ведения домашнего хозяйства, их соответствие господствовавшим идеям нового коммунального быта.The article described the different types of living conditions of women, representatives of various social strata, showing accommodation in "OGPU tawnship" luxury apartments, in home-communes, in the social behaviors, in the barracks, especially the organization of housework. The author has shown any of their respective ideas of the new communal mode of life
Source energy spectra from demodulation of solar particle data by interplanetary and coronal transport
The data on source energy spectra of solar cosmic rays (SCR), i.e. the data on the spectrum form and on the absolute SCR are of interest for three reasons: (1) the SCR contain the energy comparable to the total energy of electromagnetic flare radiation (less than or equal to 10 to the 32nd power ergs); (2) the source spectrum form indicates a possible acceleration mechanism (or mechanism); and (3) the accelerated particles are efficiently involved in nuclear electromagnetic and plasma processes in the solar atmosphere. Therefore, the data on SCR source spectra are necessary for a theoretical description of the processes mentioned and for the formulation of the consistent flare model. Below it is attempted to sound solar particle sources by means of SCR energy spectrum obtained near the Sun, at the level of the roots of the interplanetary field lines in the upper solar corona. Data from approx. 60 solar proton events (SPE) between 1956-1981. These data were obtained mainly by the interplanetary demodulation of observed fluxes near the Earth. Further, a model of coronal azimuthal transport is used to demodulate those spectra, and to obtain the source energy spectra
Off-resonance field enhancement by spherical nanoshells
We study light scattering by spherical nanoshells consistent of
metal/dielectric composites. We consider two geometries of metallic nanoshell
with dielectric core, and dielectric coated metallic nanoparticle. We
demonstrate that for both geometries the local field enhancement takes place
out of resonance regions ("dark states"), which, nevertheless, can be
understood in terms of the Fano resonance. At optimal conditions the light is
stronger enhanced inside the dielectric material. By using nonlinear dielectric
materials it will lead to a variety nonlinear phenomena applicable for
photonics applications
Wave scattering by discrete breathers
We present a theoretical study of linear wave scattering in one-dimensional
nonlinear lattices by intrinsic spatially localized dynamic excitations or
discrete breathers. These states appear in various nonlinear systems and
present a time-periodic localized scattering potential for plane waves. We
consider the case of elastic one-channel scattering, when the frequencies of
incoming and transmitted waves coincide, but the breather provides with
additional spatially localized ac channels whose presence may lead to various
interference patterns. The dependence of the transmission coefficient on the
wave number q and the breather frequency Omega_b is studied for different types
of breathers: acoustic and optical breathers, and rotobreathers. We identify
several typical scattering setups where the internal time dependence of the
breather is of crucial importance for the observed transmission properties.Comment: 17 pages, 19 figures, submitted to CHAOS (Focus Issue
Radiation Pressure Quantization
Kepler's observation of comets tails initiated the research on the radiation
pressure of celestial objects and 250 years later they found new incarnation
after the Maxwell's equations were formulated to describe a plethora of
light-matter coupling phenomena. Further, quantum mechanics gave birth to the
photon drag effect. Here, we predict a novel universal phenomenon which can be
referred to as quantization of the radiation pressure. We develop a microscopic
theory of this effect which can be applied to a general system containing
Bose-Einstein-condensed particles, which possess an internal structure of
quantum states. By analyzing the response of the system to an external
electromagnetic field we find that such drag results in a flux of particles
constituting both the condensate and the excited states. We show that in the
presence of the condensed phase, the response of the system becomes quantized
which manifests itself in a step-like behavior of the particle flux as a
function of electromagnetic field frequency with the elementary quantum
determined by the internal energy structure of the particles.Comment: Manuscript: 4 pages, 3 figure
INTELLIGENT SYSTEM OF TRAFFIC LIGHT CONTROL WITH DYNAMIC CHANGE PHASES OF TRAFFIC FLOWS ON CONTROLLED INTERSECTIONS
There was method of making an effective system of traffic-light control of the traffic through the intersections in one direction according to which the phase coefficients for each cycle of traffic-light control are computed in real- time using the data of traffic intensity detected by transport detectors. Thus, the built-in traffic control system will be dynamically adapted to the change in the intensity of traffic flows, and the structure of the cycle and its duration will be changed taking into account the parameters of the traffic flow at the intersection. Accordingly, the traffic light cycle, where each cycle has the minimum required duration, will be most effective and will ensure uninterrupted traffic, the lack of traffic jams and the convenience for the pedestrian crossings.There was method of making an effective system of traffic-light control of the traffic through the intersections in one direction according to which the phase coefficients for each cycle of traffic-light control are computed in real- time using the data of traffic intensity detected by transport detectors. Thus, the built-in traffic control system will be dynamically adapted to the change in the intensity of traffic flows, and the structure of the cycle and its duration will be changed taking into account the parameters of the traffic flow at the intersection. Accordingly, the traffic light cycle, where each cycle has the minimum required duration, will be most effective and will ensure uninterrupted traffic, the lack of traffic jams and the convenience for the pedestrian crossings
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