bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of neutral meson production with photon conversions in the MPD experiment at NICA
Authors: Kryshen E , Ivanishchev D , Kotov D , Malaev M , Riabov V , Ryabov Yu 
Published: December 2019

Abstract
The MPD experiment is aimed to study strongly interacting matter in nucleus-nucleus collisions at the future NICA collider in the energy range 4-11 GeV per nucleon pair. Neutral pion and η measurements via two-photon decays will allow the MPD experiment to extend the variety of registered particle species and will provide important information on dynamics and properties of the medium created in heavy ion collisions at NICA energies. The measurement of neutral pion and η meson spectra is also important as a first step towards the analysis of thermal photons sensitive to the temperature of the produced medium. In this contribution, the feasibility of neutral meson production measurements in the two-photon channel via photon conversions will be presented, and implications for the study of thermal photons will be discussed.
Resonant Bragg reflection of light from ZnTe-based structures with embedded CdTe monolayers
Authors: Ukleev T A , Reznitsky A N , Sel’kin A V 
Published: December 2019

Abstract
An electrodynamic model describing Bragg reflection of light from semiconductor structures with ultrathin planar layers embedded in bulk material matrix is developed. The layers are assumed to exhibit resonant optical properties in a spectral range near the short-wavelength bandgap edge of bulk material. Model calculations of the reflection spectra are performed at typical parameter values of the resonant Bragg structure containing monolayers of CdTe in bulk ZnTe.
Investigation of the optical properties of a spherical distributed Bragg reflector
Authors: Dukin A A 
Published: December 2019

Abstract
The dependence of the optical properties of a spherical distributed Bragg reflector (SDBR) on the radius of the SDBR core is studied. The SDBR reflection spectra were calculated by the method of spherical wave transfer matrices for different polarizations and different angular modal numbers of spherical waves. It is shown that if the core radius is much larger than the Bragg wavelength in the core substance, the width and spectral position of the stop-band are the same for both polarizations (TM and TE) of spherical waves and do not depend on the angular modal number of the spherical wave. If the core radius is less than several Bragg wavelengths in the core substance, a narrow dip appears in the reflection spectrum in the region of the stop-band for one polarization and some values of the angular modal number of spherical waves. It is shown that the reason for the appearance of this dip is the occurrence of a resonance in the SDBR quarter-wave layer closest to the core.
Destruction of the orbital angular momentum in combined singular beams
Authors: Akimova Ya E , Bretsko M V 
Published: December 2019

Abstract
This paper shows the dependence of the orbital angular momentum (OAM) of combined singular beams on the magnitude of the local perturbation in the holographic grating. In the absence of a perturbation of the holographic grating, the OAM acquires a maximum value numerically equal to the topological charge of the singular beam. With weak disturbances of a regular holographic grating, dips in the orbital moment appear. The depth of the dips increases rapidly with increasing disturbance. It is shown that even a weak perturbation of the lattice leads to a sharp increase in the contribution of partial beams with other topological charges. The reliability of the results obtained confirms the high degree of correlation of the intensity distribution of the original and reconstructed combined beams.
Measurement of vortex spectrum in a purely degenerate vortices array
Authors: Bretsko M V , Akimova Ya E 
Published: December 2019

Abstract
The article presents a new method for determining the basic characteristics (square of amplitude and initial phase) of purely degenerate arrays of optical vortices using intensity moments. Under purely degenerate arrays, a complex beam is assumed, in which the magnitude of the square of the amplitude of the vortices, opposite in sign of the charge, is equal, and the phases take only two values 0 and π. When the frequency parameter changes in hundredths of decimal places, the internal structure of the complex beam can be significantly changed, which is well reflected by the results obtained.
Influence of the geometric and physical parameters of the dielectric optical micro-waveguides with rectangular cross section on their losses
Authors: Zaretskaya G A , Drozdovskii A V , Cheplagin N A , Kalinikos B A 
Published: December 2019

Abstract
Formation of losses in the dielectric optical micro-waveguides of rectangular cross section is analytically studied. It is shown that the two processes are involved in the formation of the frequency characteristic of the attenuation constant: the redistribution of energy in the waveguide-environment system and the group velocity dispersion. The group velocity dispersion determined by the geometry of the waveguiding structure leads to the formation of a local maximum of the attenuation constant in the frequency response.
In situ optical monitoring of CVD growth and reactive ion etching of nanodiamonds with silicon - vacancy colour centres
Authors: Grudinkin S A , Feoktistov N A , Golubev V G 
Published: December 2019

Abstract
A method of in situ optical monitoring of the CVD growth and reactive ion etching of nanodiamonds with silicon-vacancy colour centres is presented. The method is based on measuring the time dependence of the optical reflectivity from a silicon substrate with deposited isolated nanodiamonds. Evolution of the reflectivity due to the light scattering on nanodiamonds is a result of the changes in their size and structure during growth and etching. Optical monitoring of the growth and etching processes allowed reproducible fabrication of high crystalline quality nanodiamonds.
Research of component composition of bioimplants for treatment of gum recession using a Raman spectroscopy method
Authors: Timchenko P E , Timchenko E V , Volova L T , Frolov O O , Yagofarova E F 
Published: December 2019

Abstract
Research of component composition of bioimplants for gum recession treatment using the Raman spectroscopy method is presented in this paper. Spectral assessment of the component composition of hard palate bioimplants prepared by the «Lioplast» technology before and after lyophilisation is carried out. Expanded component analysis of the researched objects using the deconvolution method shows that the difference in relative component composition of the two groups of samples is seen at wavenumbers of 1446, 1738, 1660 cm−1 (lipids & fatty acid), 852 and 938 cm−1 (proline), 1062 cm−1 (GAGs), 1204 cm−1 (tyrosine), 1555 cm−1 (amide II). The criteria that allow assessing the composition and quality of the prepared bioimplants are given on the base of spectral analysis. It is shown in the paper that the developed optical method of biomaterial assessment can be used for the process optimization and to select individual processing parameters.
Digital holographic disdrometer for precipitation monitoring
Authors: Ekimov Dmitry 
Published: December 2019

Abstract
The paper proposes and discusses the optical design and design features of a digital holographic disdrometer that combines the advantages of optical and 2D video disdrometers. The developed device has a measuring area size more than 100 cm2, the size range of the analyzed particles is up to 20 mm, the resolution is 15 μm and allows you to receive and analyze images of hydrometeors.
The use of Raman spectroscopy and methods of quantum chemistry for assessing the relative concentration of triglycerides of oleic and linoleic acids in a mixture of olive oil and sunflower seed oil
Authors: Berezin K V , Dvoretsky K N , Chernavina M L , Novoselova A V , Nechaev V V , Antonova E M , Shagautdinova I T , Likhter A M 
Published: December 2019

Abstract
The Raman spectra of five samples of sunflower seed oil and five samples of cold-pressed olive oil of various brands are recorded in the range of 500–2000 cm–1. Within the framework of the B3LYP/6-31G(d)/6-31G(d,p)/6-31+G(d,p)/6-311G(d)/6-311G(d,p)/6-311+G(d,p) methods, the structural models of eight fatty acids (oleic, linoleic, palmitic, stearic, α-linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic) are constructed, and also within the framework of the B3LYP/6-31G(d) method, the structural models of triglycerides of the first four of the above acids are obtained. The vibrational wavenumbers and intensities in the IR and Raman spectra are calculated. The Raman spectra of olive oil and sunflower seed oil were simulated by using the supermolecular approach. We investigated the dependence of the relative intensity of the vibrational bands νexp=1660 and 1445 cm–1 on the concentration of triglycerides in oils of oleic and linoleic acids and the dependence of the intensity of these bands on the degree of saturation of fatty acids.
Development of a new method for determining the parameters of a moving object based on the study of the structure of the magnetic track of colloidal solution nanoparticles
Authors: Logunov S E , Davydov V V , Rud’ V Yu 
Published: December 2019

Abstract
A new method has been developed for the study of deep-sea areas of the marine area (more than 550 m depth) based on the measurement of the parameters of a magnetic track from a moving magnetic object. A method for detecting a magnetic track from a moving magnetic object using an optical sensor is proposed. Studies of changes in the parameters of the magnetic field in the magnetic track using ferromagnetic fluid have been conducted.
Electron g-factor in coupled quantum wells CdTe and CdMnTe
Authors: Afanasiev M M , Kozyrev N V , Kirstein E , Kalevich V K , Zhukov E A , Mantsevich V N , Krivenko I S , Karczewski G , Yakovlev D R , Kusraev Yu G , Bayer M 
Published: December 2019

Abstract
In tunnel-coupled quantum wells (QWs) CdTe (20 nm wide) and CdMnTe (8 nm wide) separated by Cd0.88Mg0.12Te barrier with a thickness of L
B = 5, 7, 9, and 11 monolayers (MLs), the dependence of electron g-factor on the barrier thickness and temperature is investi-gated by means of the pump-probe Kerr rotation technique. The renormalization of the electron g-factor occurs due to the s–d exchange interaction of electrons with manganese ions in a magnetic QW. The most change of the electron g-factor value Δg = 0.25 is registered at the least barrier width of 5 MLs and temperature T = 5 K. In this case, the penetration of the electron wave function from the nonmagnetic QW into the magnetic one is estimated to be 0.6%.
The study of the spectral characteristics of biological tissues for optimization of surgical lamp parameters
Authors: Mamoshin A V , Seryogina E S , Potapova E V , Shepeleva A I , Shupletsov V V , Dunaev A V , Aladov A V , Chernyakov A E 
Published: December 2019

Abstract
During surgery, it is important for the surgeon to determine the optimal lighting conditions for contrast imaging of the operated objects. The paper analyzes various parameters of a controlled colour-dynamic surgical lamp based on a powerful led when contrasting individual organs and tissues of model animals, as well as optical parameters of the organs themselves. The results will allow developing a library of colours and lighting settings for a wide range of surgical operations.
Measuring the orbital angular momentum of light beams by using a single intensity distribution
Authors: Kovalev A A , Kotlyar V V , Porfirev A P , Kalinkina D S 
Published: December 2019

Abstract
Here, we modify and study a method for measuring the orbital angular momentum (OAM) based on angle-averaged intensity in a single transverse plane. We also simulate propagation of a superposition of two Laguerre-Gaussian modes after passing through a diffuser with a random phase. Despite the distortions caused by the diffuser, the modified method allows OAM measurement with an average error less than 10%. The main advantages of the described technique is that (i) simultaneously with the full OAM the OAM spectrum is obtained and (ii) no any optical elements are needed.
Infrared photoluminescence spectra measurements using boxcar integrator in the active baseline subtraction mode
Authors: Luferau A I , Firsov D D , Komkov O S 
Published: December 2019

Abstract
A photoluminescence (PL) measurement method using boxcar integration in the active baseline subtraction mode has been implemented. It allows for infrared PL measurements with a low duty cycle of the pump pulse, thereby minimizing the uncontrolled heating of the structure under study. The implemented method was compared to phase-sensitive detection by signal-to-noise ratio of the resulting spectra, indicating its superior performance at low duty cycles. The decrease in uncontrolled heating of the structure under study was confirmed by observing a change in the ratio of temperature-sensitive PL peaks of a test InSb/InAs/InGaAs/InAlAs/GaAs nanoheterostructure.
Metastable states of the fractal-cluster structure of alcohol-containing aqueous solutions
Authors: Shostka V I , Shostka N V 
Published: December 2019

Abstract
The paper presents the results of the study of fractal-cluster structures formed in the near-surface layer of alcohol-containing aqueous solutions. Water-ethanol mixture when changing the concentration of alcohol in water enters a new phase with a more dense packing of fluctuating structures. Molecules of alcohol, having a larger size than water molecules, when embedded in the structure of water, significantly violate it, as a result of which the structure of the system and its properties change. To visualize these structures in the surface layer of alcohol-containing aqueous solutions, the laser interferometry method was used in the work . It was found that in the range of average concentrations of alcohol in an aqueous solution, in spite of some stabilization of the structure of the system, the solutions in it have a substantial heterogeneity in the form of changing fractal-cluster structures. On the basis of the conducted studies, possible mechanisms for the transition of fractal-cluster water structures in the interaction with ethanol into spatial clathrates are shown.
High-power 0.98 µm range diode lasers based on InGaAs/GaAs quantum well-dot active region
Authors: Kornyshov G O , Payusov A S , Gordeev N Yu , Serin A A , Shernyakov Yu M , Mintairov S A , Kalyuzhnyy N A , Nadtochiy A M , Maximov M V , Zhukov A E 
Published: December 2019

Abstract
We present a study of characteristics of the edge-emitting lasers operating in the 0.98 μm wavelength range and based on a new type of InGaAs/GaAs active region – quantum well-dots (QWD). Utilizing the QWD active region in broadened 1.3 μm waveguide (BWG) allowed us to decrease the internal loss down to 0.5 cm−1 and to demonstrate the maximum output power of 13W and 50W in continuous wave (CW) and pulse operation regimes respectively. The investigation of the lasing spectra under high pulse injection currents revealed the overheating of the active region in the devices with moderate waveguide thickness (0.68 μm) in contrast with BWG devices.
Accounting the quantum-confined Stark effect on the determination of the active LED region temperature
Authors: Romanovich M M , Lamkin I A , Tarasov S A 
Published: December 2019

Abstract
The article investigates the effect of heating of the LEDs active region (AR) on the luminescence efficiency of LEDs of various spectral ranges. As a result of the work the method for contactless determination of the active LED region temperature with account the influence of the Stark effect was created. The method is based on the analysis of the long-wave part of the spectrum whose behavior primarily depends on the crystal temperature.
Effect of random macroscopic defects on kinetic phenomena in a layered semiconductor n-InSe with strong electric fields
Authors: Abdinov A Sh , Babayeva R F 
Published: December 2019

Abstract
In single-crystal n-InSe layered semiconductors at 77÷300 K, the dependence of the electrical conductivity on the strength of a strong electric field by an ultrahigh frequency (UHF) was studied. It was established that at low temperatures, the magnitude and course of the change in conductivity under the action of a strong electric field in samples with different initial (existing at 77 K) specific conductivities differ. The dependence of the electrical conductivity on the electric field strength in the most low-resistance samples is satisfactorily described by the theory of heating of charge carriers by the electric field in spatially homogeneous crystalline semiconductors, and with a decrease in the value of specific conductivity, it disagrees with this theory. It is shown that these discrepancies are due to the presence of random macroscopic defects in the crystals under study, which are formed due to the weakness of the interlayer coupling.
High-power λ = 8 µm quantum-cascade lasers at room temperature
Authors: Dudelev V V , Mikhailov D A , Babichev A V , Andreev A D , Kognovitskaya E A , Bobretsova Y K , Slipchenko S O , Pikhtin N A , Gladyshev A G , Denisov D V , Novikov I I , Karachinsky L Ya , Kuchinskii V I , Egorov A Yu , Sokolovskii G S 
Published: December 2019

Abstract
The paper presents the results of characterization of the high-power quantum cascade lasers for 8 μm spectral range. Lasers demonstrate stable generation at room temperature with the maximum output peak power of ∼ 0.9 W per facet.
Photonic crystal waveguide for difference frequency generation in terahertz range
Authors: Savchenko G M , Sokolovskii G S 
Published: December 2019

Abstract
We consider a waveguided semiconductor structure with photonic crystal core for efficient difference frequency generation. The calculation of the dispersion of the eigenmodes shows that this structure pumped by radiation with wavelengths of 1000 and 1003 nm, allows the difference frequency generation at 1 THz with a coherence length of 1 cm.
Polymer Optoelectronic Bus for High-Speed Data Transmission Systems
Authors: Manvelova T A , Tarasov S A , Ivanov N N 
Published: December 2019

Abstract
In this paper, high-speed planar waveguides of optoelectronic data bus are suggested replacing low-throughput backplane electrical interconnects. Optical polymer polydimethylsiloxane (PDMS) and cost-efficient soft lithography technology are proposed for optoelectronic bus fabrication. In accordance with polymer optoelectronic data bus fabrication process work-out results the chosen materials and technology applicability was confirmed. As an optoelectronic bus characteristics measurement results, 14 dB/cm propagation losses value was obtained by general use materials.
The technology of increasing the energy density of batteries by controlling the degree of polarization of ferroelectrics
Authors: Zubtsov V I , Zubtsova E V , Derugin V V 
Published: December 2019

Abstract
The paper deals with a power plant developed with the use of ferro-piezoelectric ceramics to increase the energy density of electric vehicle batteries. Electrochemical generator in the plant makes it possible to significantly increase electrical energy by means of controlling the degree of polarization of ferro-piezoelectric ceramics. Application of the plant in an electric vehicle increases the range on a single charge by 3.5…5 times. Efficiency factor of the power plant is about 50…55% and depends on ceramics modification and electric circuit.
Dielectric Investigations and Birefringence of PbNi1/3Nb2/3O3 Single Crystals
Authors: Polushina A D , Obozova E D , Smirnova T A , Zalesskii V G , Lushnikov S G 
Published: December 2019

Abstract
The results of studies of dielectric response and birefringence in the PbNi1/3Nb2/3O3 (PNN) single crystal are presented. An anomaly in the temperature dependence of the complex dielectric permittivity in the vicinity 153 K has been observed. It is shown that the anomaly is attributed to the transition relaxor ferroelectric state. The presence of slightly noticeable anomaly in permittivity in the temperature range of 200-210 K has been confirmed by means of optical birefringence microscopy.
Current-driven magnetization switching and dynamic spin reorientation transition in magnetic tunnel junctions
Authors: Nikitchenko A I , Pertsev N A 
Published: December 2019

Abstract
We present theoretical results on electrically induced magnetization dynamics in CoFeB/MgO/CoFeB tunnel junctions connected to a constant-current source. Our calculations take into account both the spin-transfer torque (STT) created by a spin-polarized current and a voltage-controlled magnetic anisotropy (VCMA) associated with the CoFeB|MgO interface. It is shown that the current-driven spin dynamics in an ultrathin free layer of such junction is not limited by the magnetization precession and switching, but also can have the form of a dynamic spin reorientation transition, which is caused by the combined action of STT and VCMA and gives rise to a steady precessional state. Critical current densities necessary for the appearance of different types of magnetic dynamics are calculated as functions of the free-layer thickness and in-plane aspect ratio. The spin current pumped into a normal-metal overlayer by the tunnel junction with the precessing magnetization is also evaluated.
Methods for assessing pyroelectric current in ferroelectrics with first order phase transition by dielectric measurements
Authors: Mylnikov I L , Semenov A A , Dedyk A I , Pakhomov O V , Belyavskiy P Yu , Burovikhin A P , Pavlova Yu V , Ustinov A B 
Published: December 2019

Abstract
The creation of devices based on the electrocaloric effect requires the methods for assessing pyroelectric currents at the different external parameters. Two indirect methods for calculating pyroelectric currents in ferroelectrics are considered. The first one based on the temperature-field dependences of the dielectric hysteresis loops. The second one based on the temperature-field dependences of the dielectric constant. The original method for directly estimating the magnitude of the pyroelectric currents by the charge change with thermal flux of laser radiation pulses is proposed.
Features of spin dynamics of magnetic ions and charge carriers in self-organized quantum dots CdSe/ZnMnSe
Authors: Kozyrev N V , Kirstein E , Namozov B R , Kusrayev Yu G , Zhukov E A , Sedova I V , Yakovlev D R , Bayer M 
Published: December 2019

Abstract
Self-organized disk-shaped quantum dots of CdSe embedded in diluted magnetic ZnMnSe barrier were studied by means of pump-probe time-resolved Kerr rotation (TRKR) technique at low temperature T = 7 K. In absence of the external magnetic field TRKR signal exhibits long-living spin dynamics with the decay time exceeding the period between laser pulses. Such spin dynamics is not typical for diluted magnetic semiconductors and nano-structures based on them and could be a trace of a bound magnetic polaron. Resonant spin amplification measured in transversal magnetic field up to 1 T shows the only one peak near B = 0. In B = 1 T the long-living non-precessing signal practically vanishes, while the precessing one appears with the Larmor frequency corresponding to the Mn2+ ions’ net spin precession around the magnetic field. It was found that the signal consists of three components with slightly different precession frequencies that could be due to the fine structure of the manganese spin sublevels occurring because of a stress in quantum dots.