814 research outputs found
Optical bistability in nonlinear system with two loops of feedback
A model of nonlinear optical system surrounded by two loops of feedback is
investigated. The cell with the vapor of rubidium - type atoms is taken in the
capacity of nonlinear element. Two modes of near-resonant electromagnetic field
interacting with the cell are involved in the feedback. Two-dimensional optical
bistability domain in location of input field intensities is obtained and
dependence of its form and magnitude from the system parameters (photon
detunings, feedback factor etc.) is investigated. "Input - output" relations
corresponding to different trajectories in the bistability domain are obtained.
Cross-hysteresis is studied.Comment: 7 pages, 14 figures, conference ICONO/LAT 2010, Kazan, Russi
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
Localized modes and bistable scattering in nonlinear network junctions
We study the properties of junctions created by crossing of N identical
branches of linear discrete networks. We reveal that for N>2 such a junction
creates a topological defect and supports two types of spatially localized
modes. We analyze the wave scattering by the junction defect and demonstrate
nonzero reflection for any set of parameters. If the junction is nonlinear, it
is possible to achieve the maximum transmission for any frequency by tuning the
intensity of the scattering wave. In addition, near the maximum transmission
the system shows the bistable behaviour.Comment: 5 pages, 7 figures, submitted to Physical Review
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
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