940 research outputs found
Radiation trapping in coherent media
We show that the effective decay rate of Zeeman coherence, generated in a
Rb87 vapor by linearly polarized laser light, increases significantly with the
atomic density. We explain this phenomenon as the result of radiation trapping.
Our study shows that radiation trapping must be taken into account to fully
understand many electromagnetically induced transparency experiments with
optically thick media
Enhancement of Kerr nonlinearity via multi-photon coherence
We propose a new method of resonant enhancement of optical Kerr nonlinearity
using multi-level atomic coherence. The enhancement is accompanied by
suppression of the other linear and nonlinear susceptibility terms of the
medium. We show that the effect results in a modification of the nonlinear
Faraday rotation of light propagating in an Rb87 vapor cell by changing the
ellipticity of the light.Comment: 4 pages, 3 figures Submitted to Optics Letter
Nonlinear Magneto-Optical Rotation of Elliptically Polarized Light
We predict theoretically and demonstrate experimentally an ellipticity-dependent nonlinear magneto-optic rotation of elliptically-polarized light propagating in a coherent atomic medium. We show that this effect results from a hexadecapole and higher order momenta of atomic coherence, and is associated with an enhancement of Kerr and higher orders nonlinearities accompanied by suppression of the other linear and nonlinear susceptibility terms of the medium. These nonlinearities might be useful for quantum signal processing. In particular, we report an observation of an enhancement the polarization rotation of elliptically polarized light resonant with the 5S_{1/2} F=2 -> 5P_{1/2} F=1 transition of Rb87
Precision spectral manipulation of optical pulses using a coherent photon echo memory
Photon echo schemes are excellent candidates for high efficiency coherent
optical memory. They are capable of high-bandwidth multi-pulse storage, pulse
resequencing and have been shown theoretically to be compatible with quantum
information applications. One particular photon echo scheme is the gradient
echo memory (GEM). In this system, an atomic frequency gradient is induced in
the direction of light propagation leading to a Fourier decomposition of the
optical spectrum along the length of the storage medium. This Fourier encoding
allows precision spectral manipulation of the stored light. In this letter, we
show frequency shifting, spectral compression, spectral splitting, and fine
dispersion control of optical pulses using GEM
Constitutional and legal aspect of the legal experiment of migration regulation in the Russian Federation and Germany
The article is devoted to the study of the features of the migration policy implemented in the Russian Federation as a kind of legal experimen
Humanitarian context of the principles of the judiciary in the constitutions of the countries of Eastern Europe
The article is devoted to the comparative analysis of norms of the constitutions of the countries of Eastern Europe in connection with the identification in them of the principles of the judiciary, enshrined in the special sections on the rights and freedoms of man and citize
Investigation Of Technological Properties Of Powder Of Eggplants
The aim of the article is to study and to generalize technological properties of eggplant powder, produced by infrared drying at temperatures 50-60 ºС. The results of the conducted complex of studies reflect main technological and consumption properties of the received puree that plays an important role at creating new culinary products.So, for studying technological properties of food eggplant powder, there was considered the complex of base functional-technological properties of powder, produced by infrared drying.For finding optimal conditions of rehydration of eggplant powders, there was studied the influence of such technological factors as: swelling ability; liquid; powder ratio; influence of the solvent temperature on renovation; renovation duration; degree of comminution of powders.Main parameters that influence the renovation ability of dried eggplants are investigated and studied in the article. The results of the studies of technological properties of eggplant powders prove their high rehydration properties. It gives a possibility to use powders at producing different culinary products not only for enriching them with functional ingredients, but also for giving them new technological properties.Based on the obtained results, there was elaborated and presented the new technological scheme of using renewed powders in food compositions
Human Rights Risks in the Constitutions of the American Federal States
The article presents the results of a comparative legal analysis of the constitutions of American federal states (Argentina, Brazil, Venezuela, Canada, Mexico, and USA) with a view to identifying the norms that minimize human rights risks. The examination depended on an argumentative way to deal with the revelation of legitimate wonders and cycles utilizing general logical (precise and consistent strategies, investigation and amalgamation) and explicit logical techniques. The declared axiological, functional, and institutional parameters are fully set only in the Constitution of Venezuela. Other constitutions that consider the objective specifics of the historical development of countries reflected the desired formulations in the framework of the axiology of individual rights and freedoms; prohibition of slavery; judicial protection of individual rights; isolation of a special human rights institution, etc. The objectives of the study led to the use of special legal methods. Thus, the comparative legal method contributed to the identification of resources and means of minimizing risks to human right advocacy in the foreign constitutions. The novelty of this research is identifying the norms that minimize human rights risks
Inverse Spectral-Scattering Problem with Two Sets of Discrete Spectra for the Radial Schroedinger Equation
The Schroedinger equation on the half line is considered with a real-valued,
integrable potential having a finite first moment. It is shown that the
potential and the boundary conditions are uniquely determined by the data
containing the discrete eigenvalues for a boundary condition at the origin, the
continuous part of the spectral measure for that boundary condition, and a
subset of the discrete eigenvalues for a different boundary condition. This
result extends the celebrated two-spectrum uniqueness theorem of Borg and
Marchenko to the case where there is also a continuous spectru
Vacuum Squeezing in Atomic Media via Self-Rotation
When linearly polarized light propagates through a medium in which
elliptically polarized light would undergo self-rotation, squeezed vacuum can
appear in the orthogonal polarization. A simple relationship between
self-rotation and the degree of vacuum squeezing is developed. Taking into
account absorption, we find the optimum conditions for squeezing in any medium
that can produce self-rotation. We then find analytic expressions for the
amount of vacuum squeezing produced by an atomic vapor when light is
near-resonant with a transition between various low-angular-momentum states.
Finally, we consider a gas of multi-level Rb atoms, and analyze squeezing for
light tuned near the D-lines under realistic conditions.Comment: 10 pages, 6 figures; Submitted to PR
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