Self-focusing of CW laser beam with variable radius in rubidium atomic vapor
Optics Communications. 2019. Vol. 431. P. 131-135.
Sautenkov V. A., Shneider M. N., Saakyan S. A., Vilshanskaya E. V., Murashkin D. A., Arshinova I. D., Zelener B. V., Zelener B. B.
Self-focusing of cw laser beam in a rubidium atomic vapor was studied. The beam radius and power at the entrance of a rubidium vapor cell were variable parameters. A steep grow of the self-focusing threshold power for the small beam radius (≤ 30 μ m) was observed. Our experimental data are in a qualitative agreement with the recently published theoretical results obtained for a conventional non-resonant gas. Additional experiments in the resonance and transparent non-resonant media are suggested in order to check and extend our measurements.
Research target: Physics
Priority areas: engineering science
, , Optics Letters 2018 Vol. 43 No. 4 P. 651-654
We study the output emission statistics of a random continuous-wave Raman fiber laser. The signal evolution is governed by a generalized nonlinear Schrödinger equation (NLSE) with inserted gain. The statistics are close to the Rayleigh one, and the deviations are caused by the Kerr nonlinearity. To characterize the deviations, we analytically find the mean of ...
Added: February 8, 2018
Second harmonic generation by metal core - dielectric shell spherical nanoparticles: spatial vs. plasmon resonances
, , , Journal of Physics: Conference Series 2018 Vol. 1124 No. 5 P. 051028
An analytical study of the second harmonic generation by metal core - dielectric shell spherical nanoparticles was performed. Dependences of the second harmonic intensity on the dielectric shell thickness were calculated. We demonstrated that the thin coating allows tuning surface plasmon resonance wavelength, whereas in presence of the thick shell spatial Mie resonances occur. Estimated ...
Added: December 9, 2020
Understanding the Second-Harmonic Generation Enhancement and Behavior in Metal Core–Dielectric Shell Nanoparticles
, , Journal of Physical Chemistry C 2018 Vol. 122 No. 27 P. 15635-15645
To explain recently observed up to 50-fold enhancement of the second harmonic (SH) signal from gold nanoparticles after depositing of a thin dielectric layer, we perform an analytical study of the SH generation by metal core-dielectric shell spherical nanoparticles (NPs). We derive analytical expressions for the SH intensity accounting for electric dipole and quadrupole impacts. ...
Added: December 9, 2020
Nonresonant Local Fields Enhance Second-Harmonic Generation from Metal Nanoislands with Dielectric Cover
, , et al., Physical Review Letters 2018 Vol. 120 No. 11 P. 113902
We study second-harmonic generation from gold nanoislands covered with amorphous titanium oxide (TiO2) films. As the TiO2 thickness increases, the plasmon resonance of the nanoislands shifts away from the second-harmonic wavelength of 532 nm, diminishing the resonant enhancement of the process at this wavelength. Nevertheless, the second-harmonic signal is enhanced by up to a factor of ...
Added: December 9, 2020
, , et al., Journal of Physics: Conference Series 2020 Vol. 1695 No. 1 Article 012135
In this paper, we demonstrate the results of a study of the optical absorption properties of graphene integrated with silicon nitride O-ring resonator. We fabricated an array of O-ring resonators with different graphene coverage area atop. By measuring the transmission spectra of nanophotonic devices with and without graphene, we calculated the effective absorption coefficient of the graphene on a ...
Added: April 28, 2021
, , , Laser Physics Letters 2020 Vol. 17 No. 4 P. 045901
In this paper we present measurements and comparison of SPP propagation length at the practically important telecom wavelength (1560 nm) as well as in the near-infrared and visible spectral ranges. The measurements were carried out for plane SPP waves excited on Ag film surface using optical microscopy of SPP waves in the far field. We ...
Added: January 15, 2021
Сканирующий безапертурный микроскоп ближнего оптического поля - прибор для исследования оптических свойств поверхности с нанометровым разрешением
, , et al., Известия РАН. Серия физическая 2017 Т. 81 № 12 С. 1709-1714
Описаны принципы работы безапертурного сканирующего микроскопа ближнего оптического поля (ASNOM). Зондом в приборе служит металлизированная игла атомно-силового микроскопа, и оптическое взаимодействие с объектами на поверхности локализовано вблизи ее острия размером в несколько нанометров. Тело иглы имеет длину в несколько микрон, и это обеспечивает высокую эффективность ее электромагнитного взаимодействия с падающими на нее извне и излучаемыми ...
Added: December 6, 2020
Temperature distribution in driven granular mixtures does not depend on mechanism of energy dissipation
, , , Scientific Reports 2020 Vol. 10 Article 693
We study analytically and numerically the distribution of granular temperatures in granular mixtures for different dissipation mechanisms of inelastic inter-particle collisions. Both driven and force-free systems are analyzed. We demonstrate that the simplified model of a constant restitution coefficient fails to predict even qualitatively a granular temperature distribution in a homogeneous cooling state. At the same time we reveal ...
Added: February 25, 2020
, , Materials Letters 2017 Vol. 206 P. 64-66
To obtain a correct estimate of the microhardness dependence on the size of nanocrystals, the microhardness of amorphous-nanocrystalline samples with the same fraction of the crystalline phase and the same composition of the amorphous matrix but different sizes of nanocrystals was studied. It is shown that the dependence of microhardness on the nanocrystal size in the size range ...
Added: February 22, 2018
, , Международный журнал экспериментального образования 2014 № 1 С. 98-101
Devices of nanorelocation with the probes, the executing operations necessary for formation of quantum points are developed. Options of execution of devices are shown. ...
Added: January 20, 2014
М. : National Instruments Russia, 2017
Содержание сборника составляют доклады с результатами оригинальных исследований и технических решений, ранее не публиковавшиеся. Мы надеемся, что предлагаемый сборник окажется полезным для специалистов, работающих в различных областях науки и техники, для широкого круга преподавателей, аспирантов и студентов ВУЗов, а также для преподавателей средних школ и технических колледжей. ...
Added: May 10, 2017
, , et al., Journal of the American Ceramic Society 2019 Vol. 102 No. 5 P. 2745-2751
Single crystal of TlCl was doped with NIR photoluminescent univalent bismuth cations by prolonged immersion in liquid bismuth metal. The ion exchange Tl+ + Bi0 ↔ Tl0 + Bi+ at the crystal surface with subsequent Bi+ migration to the bulk are expected to drive the doping process. Contrary with Bi‐doped TlCl crystals, grown by Bridgman method, the ion exchange does ...
Added: February 8, 2019
, , Polymer Science - Series C 2018 Vol. 60 No. Supplement 1 P. 148-159
Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the ...
Added: November 30, 2018
, , et al., IOP Conference Series: Materials Science and Engineering (MSE) 2020 Vol. 781 No. 1 P. 012011-1-012011-5
Spectral characteristics of WSi and NbN superconducting single-photon detectors with different surface resistance and width of nanowire strips have been investigated in the wavelength range of 1.3-2.5 µm. WSi structures with narrower strips demonstrated better performance for detection of single photons in longer wavelength range. The difference in normalized photon count rate for such structures ...
Added: December 10, 2020
, , et al., Inorganic Materials 2020 Vol. 56 No. 8 P. 828-835
We have studied and optimized conditions for spontaneous flux growth of TbCr3(BO3)4 crystals. Phase relations in the pseudoternary system TbCr3(BO3)4–K2Mo3O10–B2O3 have been studied in the temperature range 900–1130°C and the single-phase terbium chromium borate crystallization field has been mapped out. It has been shown that increasing the TbCr3(BO3)4 content of the starting high-temperature solution leads to a rhombohedral-to-monoclinic phase ...
Added: October 22, 2020
, Эпистемология и философия науки 2019 Т. 56 № 1 С. 169-184
The framework of simple opposition realism - anti-realism is not enough to analyze the views on the reality of unobservable objects of quantum theory. First, it is necessary to distinguish between realism in relation to the theory and realism in relation to the theory’s objects. Secondly, realism in relation to classical objects can be combined, ...
Added: February 12, 2020
Unconventional superconductivity in low density electron systems and conventional superconductivity in hydrogen metallic alloys
, JETP Letters 2016 Vol. 103 No. 11 P. 728-738
In this short review, we first discuss the results, which are mainly devoted to the generalizations of the famous Kohn–Luttinger mechanism of superconductivity in purely repulsive fermion systems at low electron densities. In the context of repulsive-U Hubbard model and Shubin–Vonsovsky model we consider briefly the superconducting phase diagrams and the symmetries of the order parameter ...
Added: November 18, 2016
On the Spin Depolarization of a Hall Ferromagnet in the Vicinity of ν = 1 in Two-Dimensional Electron Systems Based on ZnO
, , , JETP Letters 2019 Vol. 110 No. 4 P. 296-300
The behavior of the degree of spin polarization and the specific exchange energy near the Hall ferromagnetic state with filling factor ν = 1 in strongly interacting two-dimensional electron systems in MgZnO/ZnO heterostructures is investigated. These characteristics have been determined by measuring the spectra of inelastic light scattering by the collective excitations of the electron ...
Added: October 31, 2019
Electronic band structure of phosphorus-doped single crystal diamond: Dynamic Jahn-Teller distortion of the tetrahedral donor ground state
, , et al., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 P. 115153-1-115153-10
The electronic band structure of the phosphorus-doped high-quality high-pressure and high-temperature– grown single crystal diamond was studied by infrared absorption, magneto- and electron paramagnetic resonance spectroscopy, and first-principles calculations. The complete picture of the 1s → np± and 1s → np0 (n = 2, 3, 4) donor transitions with new 1s →3p0,4p0 and 1s →4p± transitions allowed us ...
Added: October 22, 2020
Intrinsic arrested nanoscale phase separation near a topological Lifshitz transition in strongly correlated two-band metals
, , et al., Superconductor Science and Technology 2015 Vol. 28 No. 2 P. 024005-1-024005-8
The arrested nanoscale phase separation in a two-band Hubbard model for strongly correlated charge carriers is shown to occur in a particular range in the vicinity of the topological Lifshitz transition, where the Fermi energy crosses the bottom of the narrow band and a new sheet of the Fermi surface related to the charge carriers ...
Added: March 12, 2016
, , et al., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 99 No. 4 Article 045305
The integer quantum Hall effect is a well-studied phenomenon at frequencies below about 100 Hz. The plateaus in high-frequency Hall conductivity were experimentally proven to retain up to 33 GHz, but the behavior at higher frequencies has remained largely unexplored. Using continuous-wave terahertz spectroscopy, the complex Hall conductivity of GaAs/AlGaAs heterojunctions was studied in the ...
Added: December 11, 2020
, , et al., Физика и химия обработки материалов 2017 № 6 С. 5-17
Изучено влияние облучения в установке Плазменный фокус PF-1000 экстремальными энергетическими потоками быстрых ионов дейтерия (Ei≈100 кэВ, плотность мощности qi≈1011-1012 Вт/см2, длительность импульса ti≈10-50 нс) и дейтериевой плазмы (qpl≈109- 1010 Вт/см2, tpl≈50-100 нс) на структуру поверхностного слоя молибденовой пластины с учетом его плавления, частичного испарения и закалки расплава. На облученной поверхности обнаружено образование капельных структур, пор, ...
Added: December 25, 2017
M. : Faculty of Physics, MSU, 2017
The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. The aim of these conferences is to exchange information and views among the members of the international scientific community in the general field of Low Temperature Physics. It ...
Added: October 1, 2017
Estimation of Intraband and Interband Relative Coupling Constants from Temperature Dependences of the Order Parameter for Two-Gap Superconductors
, , et al., Journal of Superconductivity and Novel Magnetism 2016 Vol. 29 No. 4 P. 1111-1116
We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB2. The experimental L,S(T ) are wellfitted with a two-gap model based on Moskalenko and Suhl system of equations (supplemented with a BCS integral renormalization). From the fitting procedure, we estimate the key ...
Added: March 19, 2016