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