bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization selective metasurface formed by interference laser writing
Authors: Andreeva Ya M , Koval V V , Sergeev M M , Itina T
Published: April 2020

Polarization dependent optical response of the periodically nanostructured SiO2-Ag nanocomposite material is investigated. As a result of the laser-based surface structuring, the reflection is found to be particularly enhanced and blueshifted for parallel polarisation. This result is attributed to the interaction between photonic and plasmonc resonances, namely to the coupling of the grating caused Rayleigh-Wood anomaly mode (described by using grating theory) with localized surface plasmon modes of the embedded Ag nanoparticles (described by using effective medium approach). The laser-induced formation of such metasurface allows precise control of the effect that is essential for practical application in photonics devices and optical filters.
Third harmonic generation from polymer nanocomposite with embedded CdSe quantum dots
Authors: Antropov I.M. , Chizhov A.S. , Abrashitova K. A. , Bessonov V.O. , Fedyanin A.A
Published: April 2020

In this paper we fabricate nonlinear optical nanocomposite based on CdSe quantum dots mixed with commercial photoresist SU-8, which can be structured by two-photon polymerization lithography. The distribution of quantum dots in the polymer was measured by transmission electron microscopy. Nonlinear optical properties of nanocomposite films were studied by third harmonic generation technique. We estimated the nonlinear cubic susceptibility of our nanocomposite.
Superconducting Diamond as a platform for quantum technologies
Authors: Coleman C , Mazhandu F , Reddhi S J , Aslan T , Wei D , Huynh C , Gnauck P , Bhattacharyya S
Published: April 2020

We present some of the anomalous transport features that have recently been observed in boron doped diamond, these include the re-entrant Bosonic Insulating peak, Zero Bias Conductance anomaly and non-linear magnetoresistance. The features, related to confined condensate phase and bound states, are expected to interesting for novel device functionality particularly in low dimensional device elements such as superconducting resonators and phase slip qubits. The fabrication techniques required to produce such device elements are also discussed, including our preferred method of He ion source focused Ion beam (FIB) patterning.
Modal analysis of anapoles
Authors: Colom Rémi , Stout Brian , Mcphedran Ross , Bonod Nicolas
Published: April 2020

The resonant interaction between light dielectric scatterers can yield to a resonant light scattering process and to a strong enhancement of the near field intensities at a deep sub-wavelength scale. While Fano resonances can be observed in the scattering spectrum of Mie scatterers, the spectrum of the internal field enhancement is composed of a set of peaks that feature Lorentzian shapes. The question is to know how to optimize the internal field enhancement and how to predict the maximum of the internal field enhancement with respect to the far field response. Here, we derive a pole expansion of the scattering operator to perform a modal analysis of the external and internal field spectra. This pole expansion provides a suitable mathematical description of the Fano resonances observed in the scattering spectrum and of the Lorentzian peaks observed in the internal field spectrum. This modal analysis is also used to predict the maxima of the internal field, i.e. the frequency that yields the strongest field intensity inside the dielectric scatterer.
Regimes of optical mode coupling: from core-shell single particle to dimer
Authors: Dmitriev Alexey A , Rybin Mikhail V
Published: April 2020

We study a transformation of a core-shell dielectric rod into a dimer by pulling the core rod out of the shell. We present simulated scattering spectra of two infinite dielectric rods with dipole Mie resonances tailored to the same frequency by choice of the refractive indices ratio. We identify a transition between weak and strong coupling regimes by examining the peak splitting of the dipole Mie resonance. We find that the splitting increases as the distance between the rod centres decreases. This behaviour is kept for all configurations: core-shell, eccentrically embedded rod and dimer.
Bright solitons in spontaneously formed polariton networks
Authors: Gavrilov S. S.
Published: April 2020

Bright solitons in a polariton fluid are excitations with a comparatively high intensity that flow without dissipation in spite of a finite lifetime of polaritons. Under resonant driving conditions, bright polariton solitons can be created using a two-beam excitation scheme which includes a plane-wave pump and a focused beam injecting a soliton at a certain location [O. A. Egorov et al., PRL 102, 153904 (2009)]. Here we discuss a new mechanism of soliton formation which takes place under plane-wave driving in a perfectly uniform microcavity wire—i.e., with no writing beams or seeding inhomogeneities. The key phenomenon underlying formation of solitons in this case is the spontaneous breaking of continuous symmetry and onset of periodic spin networks [S. S. Gavrilov, PRL 120, 033901 (2018)].
Semi-transparent lossy surfaces for cutoff of the fields in microwave shadow domain
Authors: Tatarnikov D V , Generalov A A
Published: April 2020

Semi-transparent surfaces for cutoff of the fields in the shadow domain of an antenna are considered. For relatively large screen sizes, the analytical synthesis procedure of the grid impedance is formulated in the approximation of geometric optics (GO), which provides a purely real impedance. For smaller sizes, a numerical procedure to synthesize realizable complex impedance has been implemented. A prototype of the compact antenna system with lossy semi-transparent impedance surface has been developed. No noticeable degradation of the antenna gain in the open space domain has been detected. Perspectives for further reduction in the screen size by employment of a dual-current layer are discussed; estimates of the serial impedance of the magnetic portion are provided.
Infrared localized surface plasmon dark multipole modes generated on subwavelength corrugated metal disks
Authors: Bulgakova V V , Gerasimov V V , Hafizov R R , Lemzyakov A G
Published: April 2020

Terahertz (THz) radiation is very promising for chemical and biological sensing. One of the ways to realize a THz sensor is exciting multipole localized surface plasmon resonances (LSPRs) on subwavelength corrugated metal disks. In this paper, numerical modeling and analysis of LSPRs on a periodic array of such structures were made. At normal incidence of the incoming wave, only dipole resonances can be excited. An additional C-shaped resonator placed in the vicinity of the disk produces dark multipole modes (quadrupole, hexapole, octupole, and decapole ones) due to hybridization of these modes with the brigth dipole mode of the C resonator. Besides, multipole modes can be excited at oblique illumination of the structure. With increase in the incident angle, the multipole resonances become stronger. The high Q-factor resonance modes observed for PEC disks are wider or disappeared in case of Drude gold permittivity.
Graphene-based optically tunable structure for terahertz polarization control
Authors: Grebenchukov Alexander , Zaitsev Anton , Masyukov Maxim , Litvinov Egor , Kvitsinsky Anatoly , Demchenko Petr , Kovalska Evgeniya , Baldycheva Anna , Khodzitsky Mikhail K.
Published: April 2020

We present a theoretical model of optically tunable graphene-based structure for polarization characteristics control of transmitted terahertz (THz) wave. The experimental verification was performed using a THz time-domain polarimetry setup. The tunability is achieved by applying an external optical pumping and magnetic field. The structure shows the possibility for dynamical control of ellipticity and azimuth angles of polarization state of THz radiation in a transmission mode. This study indicates a strong potential for using graphene-based structures for polarization sensitive applications such as THz wireless communications and biomedical research.
Nano engineering of quantum multifunctional structures with interferometers by mechanical “bottom-up” assembling
Authors: Orlov A.P. , Frolov A.V. , Smolovich A.M. , Lega P.V. , Shavrov V.G. , Zybtsev S.G. , Pokrovskiy V.Ya. , Fam V.Ch. , Irzhak A.V. , Bhatchatarria S. , Kolodev V. , von Gratoswki S. , Pakizeh T.
Published: April 2020

The creation of 3D ordered nanostructures represents an important technological problem for scientific research, nano-electronics, and nano-sensorics, because of the fact, that various nano-objects with useful physical and functional properties are synthesized as large arrays, but the selection, transfer and formation of 2D and 3D nanostructures should be done using tools comparable in size to the manipulated nano-objects. This paper describes the results of fabricating of the samples of suspended CNT and nanowire rings, presenting the configuration of quantum interferometers. The experiments on nanointegration of resonators are done by mechanical “bottom-up” assembling using nano-tweezers based on Ti2NiCu shape memory alloy. The prospects of the application of the mechanical bottom up nanointegration of 2D and 3D multiple resonators structures for wide band meta-surfaces and meta materials creation are discussed.
Optical properties of thin graphene oxide films and their biosensing applications
Authors: Komisar D A , Krivova G M , Stebunov Y V , Yakubovsky D I , Ermolaev G A , Arsenin A V , Volkov V S
Published: April 2020

Graphene oxide (GO) is a promising platform to realize immobilization matrices for plasmonic biosensors. Here, we discuss various aspect of the deposition of GO thin films, their optical properties, and the influence of GO linking layers on biosensing sensitivity. Using spectroscopic ellipsometry, we obtain dielectric functions of thin GO films deposited by spray-coating in the visible and near-infrared ranges. In addition, we demonstrate that the optimization of GO linking layers may sufficiently increase the sensitivity of SPR biosensing.
RF-resonator for clinical MR imaging in urology and andrology
Authors: Koreshin E A , Zubkov M A , Glybovski S B
Published: April 2020

New diagnostic visualisation and quantification methods of nerve tracks are needed in andrology and urology applications. In order for magnetic resonance imaging (MRI) to properly image the nerves of interest a dramatic signal-to-noise ratio (SNR) increase is required. For this purpose, radiofrequency (RF) resonator based on the birdcage operating principles has been designed, fabricated, measured and compared to simulation model obtained by time domain method in CST microwave studio. The resonator concentrate RF magnetic field in the centre of the resonator, while electric field remains on the edge thus preventing tissue heating. Design and parameters of resonator was optimised for human MRI on 1.5T scanners. Using the resonator allowed to improve RF-safety for 2 times, transmit efficiency for 10 times and SNR for 14 times compared to body coil only system. Measured and computed resonance frequencies and transmit efficiency are in good agreement.
Suppression of high-order multipole moments in a resonant periodic dipole chain
Authors: Kornovan D. F. , Baryshnikova K. V. , Petrov M. I.
Published: April 2020

In this work we study the properties of optical states in transverse subdiffractional dipolar chains of periodically spaced scatterers. We demonstrate that in this system there are states with low values of emission rates, and we explain this as a reduction of different multipolar contributions up to high values of orbital angular momentum. We also show that the emission rate for these states decreases as ∼ N
−6.76 with the number of scatterers.
Synthesis of perovskite nanoparticles in microfluidic chips
Authors: Koryakina I , Pushkarev A , Makarov S V , Zyuzin M V , Evstrapov A A
Published: April 2020

Organic-inorganic lead halide perovskites are the class of materials with unique physical properties that have attracted an interest in scientific and industrial communities. With microfluidic devices it is possible to obtain high-quality nanoparticles (NPs) based on perovskites of different physico-chemical properties such as size, shape, chemical composition. The aim of this work is to achieve the stable and reproducible synthesis of perovskite NPs on the microfluidic device. To obtain perovskite NPs two microfluidic chips (MFCs) of different topologies are investigated, where a porous membrane is introduced into MFCs using different methods: first method includes direct incorporation of commercial membrane into straight channel of MFC resulting in a "sandwich" structure, the second method implied membrane preparation as a part of a chip fabrication process. The results revealed that microfluidic devices allow synthesis of monodisperse perovskite NPs.
Optical manipulations via auxiliary substrates
Authors: Kostina N A , Ivinskaya A N , Kislov D A , Ginzburg P , Shalin A S
Published: April 2020

We report flexible optomechanical manipulations by the help of surface and volumetric modes of the substrate. Optical binding effect can be sufficiently enhanced due to both surface plasmon-polariton and hyperbolic modes of the structure. Volumetric modes of the structure provide optical pulling force for inclined incident plane wave, while surface waves cause enhancement of the optical trapping force under Gaussian beam illumination. Moreover, antitrapping effect can occur for specific positions of the beam waist.
Enhancement of the quantum dot photoluminescence using transfer-printed porous silicon microcavities
Authors: Kryukova I S , Dovzhenko D S , Rakovich Yu P , Nabiev I R
Published: April 2020

Enhancement of the photoluminescence signal intensity from organic and inorganic fluorophores increases the sensitivity of operation of optical sensors, detectors, and photonic diagnostic assays. Here, we have engineered and compared optical and fluorescence-enhancing properties of two types of one-dimensional porous silicon photonic crystals: a transfer-printed microcavity based on the freestanding photonic crystal and a conventional “one-piece” microcavity created on a monocrystalline silicon substrate. Comparative analysis of the eigenmodes and the photonic bandgaps of both types of microcavities demonstrated a high quality of transfer-printed microcavities and good correlation of their reflection spectra with the spectra of “one-piece” microcavities. Moreover, embedding of a highly concentrated solution of quantum dots (QDs) in the eigenmode localization region of transfer-printed microcavity was followed by three-fold reduction of the full-width-at-half-maximum of their luminescence spectrum at the microcavity eigenmode wavelength, thus confirming a weak coupling regime of QD exciton and microcavity eigenmode interaction and significant enhancement of QD luminescence within the microcavity.
Ultrafast acoustic switching of an optically pumped cavity polariton system in the bistable regime
Authors: Demenev A. A. , Gavrilov S. S. , Sherbakov A. V. , Yaremkevich D. D. , Kukhtaruk S. M. , Yakovlev D. R. , Kulakovskii V. D. , Bayer M.
Published: April 2020

Nonequilibrium transitions are investigated in a plane exciton-polariton system with complex acousto-optical excitation: stationary resonant optical excitation of polaritons along the normal to the surface of the resonator and picosecond strain pulses causing reversible exciton energy perturbations. It is shown that acoustic pulses can be used for ultrafast switching of the optical response of a bistable polariton system. Switching is experimentally implemented in a high-Q GaAs microcavity.
Nonlinear optical properties of Sponge Si/Au nanoparticle
Authors: Larin Artem , Ageev Eduard , Shiker Anna , Nomine Alexandre , Makarov Sergey , Zuev Dmitry
Published: April 2020

Plasmon sponge nanostructures have occupied a special role in the field of plasmonics and nanophotonics: sensors and advanced source of white emission. If the pores of a golden spongy nanostructure are filled with silicon, the result will be a promising source of broadband radiation with high efficiency due to the localization of the field by a structure with a high surface-to-volume ratio. This paper presents the results of photoluminescence generation with multiphoton absorption and second-harmonic generation obtained from hybrid sponge Si/Au nanoparticles. The particles have been fabricated by femtosecond laser ablation at room temperature in the air. Experiments have shown the ability to generate broadband photoluminescence in the range of 500 – 800 nm (0.93 eV). The obtained results can be applied for creation of white light luminescent metasurfaces and advanced nanophotonic spectroscopy devices.
Multi-spectral interference imaging using laser-induced plasma light source
Authors: Machikhin A S , Polschikova O V , Vlasova A G , Gorsky E V , Churin A E , Subin A N
Published: April 2020

Interference imaging techniques are widely used for studying surface and internal structure of various objects. By varying the operating wavelength of the interference system, one can also obtain the information about the spectral properties of the inspected specimen. For multi-spectral interference imaging applications, wide-band high power light sources are necessary. Most of the existing sources suffer from speckle noise, low brightness or high price. In this paper, we demonstrate the applicability of a laser-induced plasma light source for interference imaging and quantitative phase measurements. Narrow-band spectral filtration of its illumination within a wavelength range 240-2600 nm allows to design cost-effective schemes for a variety of metrological applications including digital holography and spectral-domain optical coherence tomography.
Near-field scanning magneto-photoluminescence of composite fermions in In(Ga)P/GaInP quantum dots
Authors: Mintairov A M
Published: April 2020

We measured spatial and magnetic field dependence of photoluminescence (PL) spectrum of In(Ga)P/GaInP quantum dots (QDs) having up to 8 electrons and quantum confinement ħω
0 down to 2 meV using low temperature (10K) near-field scanning optical microscope (NSOM) providing spatial resolution ∼20 nm and external magnetic field up to B0=10 T. Using these measurements we identified QDs having Wigner-Seitz radius up to 2 and internal magnetic field B
int up to 15 T, corresponding to Landau level filling factor v at zero field ν
0 3, 5/2, 2/5 and 1/5. In magneto-PL spectra we observed features related to integer and fractional quantum Hall states and identified composite fermion (CF) states corresponding to Wigner molecule isomers (1, 5) and (0, 6). Our results demonstrate perspectives of using In(Ga)P/GaInP QD structures, providing deterministic localization of CFs in zero external magnetic field, in “magnetic-field-free” topological quantum gates.
Optical and luminescent properties of ceria nanoparticles produced by gas phase method
Authors: Myshkina A V , Bazhukova I N , Kiryakov A N , Sokovnin S Y , Il’ves V G , Kasyanova V V
Published: April 2020

The study on luminescent and optical properties of ceria nanoparticles allow one to indirectly assess the defectiveness of the material crystal lattice. The decomposition of the luminescence spectrum in the Gaussian bands shows the presence of Ce3+ ions in the CeO2 crystal lattice, as well as optical active centers, probably associated with oxygen vacancies. These characteristics permit us to estimate the relative amount of Ce3+ ions in the crystal lattice and could be considered as an important prerequisite for the use of nanoparticles as redox agents in industry and medicine.
Magneto-optical properties of plasmonic hyperbolic metamaterials
Authors: Novikov V B , Kolmychek I A , Pomozov A R , Leontiev A P , Napolskii K S , Murzina T V
Published: April 2020

The results of the experimental studies and numerical simulation of optical and magneto-optical properties of composite structures containing gold nanorods in porous anodic alumina templates and coated by a continuous nickel film are presented. We reveal two features in the Faraday rotation spectra of the structures in the vicinity of the wavelengths of 540 nm and 810 nm, which correspond to the epsilon-near-pole and epsilon-near-zero regions, respectively. Experimentally observed distinct enhancement of magneto-optical effects in the structures in the spectral vicinity of these points are consistent with the simulation results and open up novel opportunities for magnetic-field-assisted light manipulation.
Electrophysical parameters of P3HT:PCBM solar cells
Authors: Onishchuk D A , Parfenov P S , Litvin A P , Shcherbinin D P , Baranov A V , Fedorov A V
Published: April 2020

Using the dark capacitance–voltage and current–voltage characteristics we analyzed the electrophysical parameters of P3HT:PCBM solar cells with addition of PbS nanocrystals. The influence of the device architecture on the built-in potential value and ideality factor are considered. The process of space-charge limited current characterizing is also described.
Emitting properties of a-Si:C:H films with a gold submicron grating
Authors: Pavlov S I , Dyakov S A , Samusev A K , Nashchekin A V , Tanklevskaya E M , Feoktistov N A , Gippius N A , Tikhodeev S G , Pidgayko D , Pevtsov A B
Published: April 2020

In this study reflection and photoluminescence spectra of a-Si:C:H thin film with gold grating on it was examined theoretically and experimentally. The hydrogenated amorphous amorphous silicon-carbon alloy films were fabricated by the PECVD technique. Arrays of gold stripes with different gold width were created by lift-off e-beam lithography. Reflection, and PL spectra has been measured by a Fourier imaging spectroscopy. The theoretical calculations are in a good agreement with experimental results. From the PL spectra it follows, that the TE polarization gives sharper and more efficient PL signal than the TM polarization, and PL efficiency almost does not depend on gold stripes widths. It was shown that only in TE modes the PL outcouples from the gratings owing to the fact that there is no plasmon’s affect in this polarization.
Acousto-optic properties of metamaterials
Authors: Petrov N I , Pustovoit V I
Published: April 2020

The possibility of efficiently using metamaterials in acousto-optics has been demonstrated. Diffraction of light in heterogeneous medium with non-uniform spatial distribution of dielectric nanoparticles taking into account absorption of light is investigated. It is shown that by changing the concentration of dielectric nanoparticles in the medium, complete elimination of side oscillations and suppression of the “tails” of the diffraction reflection curve can be achieved. The possibility of controlling the hardware function of acousto-optic devices by changing the material, concentration, size, shape and spatial orientation of the inclusions, as well as the polarization of the incident radiation is shown.
Fabrication of nano-micro-sized 14C enriched constructive elements in plasma deactivation treatment of irradiated reactor graphite
Authors: Petrovskaya A S , Kladkov A Yu , Surov S V , Stakhiv M R , Tsyganov A B
Published: April 2020

We propose a new fabrication method for the meta-material said "beta-active nano-sandwich" (for example, enriched with radioisotope 14C, etc.) by a plasma sputtering technology that we are developing for the decontamination of nuclear power plants constructions. This new kind of beta-active nano-materials can be a valuable product resulting from nuclear deactivation process and be useful for nuclear medicine applications and creation of advanced beta-voltaic batteries. Plasma sputtering device operation is based on a “dry” plasma decontamination method – the ion sputtering of radionuclides from the radioactively polluted surface (e.g., irradiated reactor graphite). We present calculations results of the plasma sputtering device operating parameters: anode and cathode surface temperature, discharge input power density, equivalent current density, ion sputtering and mass-transfer rates of nano - layers from the processed graphite surface.
Sublayer induced enhancement of electric and magnetic dipole scattering of dielectric nanoparticles
Authors: Pidgayko Dmtiry , Ladutenko Konstantin , Bogdanov Andrey
Published: April 2020

In this paper, we numerically investigate the effect of a low-index sublayer on resonant dielectric nanoparticle placed on a high-index substrate. We show that the scattering cross section depends in a resonant manner on the thickness of the sublayer. In addition, the position of the maxima can be controlled by changing the angle of incidence and polarization of the incident radiation. Finally, we give an example of flexible control of the electric and magnetic dipole responses by changing the angle of incidence and polarization in a system with a subwavelength sublayer.
Nonlinear optical properties of tellurium oxide nanoclusters
Authors: Roginskii E M , Smirnov M B , Noguera O , Masson O , Thomas P
Published: April 2020

The finite field method using ab initio hybrid functional approach was applied to estimate nonlinear properties of the cluster based on paratellurite crystal structure. The good agreement was found with previously reported data.The method demonstrate high efficiency in prediction of nonlinear properties for a wide ensemble of sufficiently large polyatomic clusters.
Interaction between dielectric particles enhances the Q factor.
Authors: Bulgakov E. N. , Pichugin K.N. , Sadreev A. F.
Published: April 2020

We consider resonant modes of two dielectric identical particles which can be classified as symmetric and anti symmetric combinations of the resonant modes of individual particles. We show that an approaching of two particles gives rise to an avoided crossing of resonant poles because of interaction between the disks. That in turn results in strong enhancement of the quality factor factor of two disks compared to isolated disks.
Formation of phase clusters and chimera states in hierarchical networks of Josephson junctions
Authors: Safina Olga S. , Tsironis George P.
Published: April 2020

We demonstrate regimes such as cluster synchronization and chimera states in a hierarchical network based on Josephson Junctions. We find that the fractal spectrum of possible system frequencies of the system forms a devils staircase. Hierarchical networks have interesting fractal features and could be used for scaling of some properties of fractal networks. In our structure, Josephson Junctions are connected through electric currents in the form of a Cayley tree.
Non-Huygens invisible metasurfaces
Authors: Shamkhi Hadi K. , Baryshnikova Kseniia V. , Sayanskiy Andrey , Terekhov Pavel D. , Gurvitz Egor A. , Valero Adria Canos , Karabchevsky Alina , Kapitanova Polina , Evlyukhin Andrey B. , Belov Pavel , Kivshar Yuri , Shalin Alexander S.
Published: April 2020

All-dielectric nanophotonics attracts more and more attention nowadays due to the possibility to control and configure light scattering on high-index semiconductor nanoparticles. It opens a room of opportunities for the designing novel types of nanoscale elements and devices, and paves a way to advanced technologies of light energy manipulation. One of the most perspective and interesting effects is directive light scattering provided by the so-called Kerker and anti-Kerker effects giving a possibility to realize Huygens source of light, fully transparent metasurfaces, different types of nanoatennae etc. Another one corresponds to the realization of so-called “anapole states” providing near-zero scattering accompanied with strong near-fields. Here we briefly review some new results on the induced invisibility regarding fully transparent metasurfaces based on the simultaneous cancellation of the forward and backward scattering via particular optical responses of multipoles (similar to Kerker effect), and invisible objects and structures governed by the novel type of anapoles – hybrid anapole states.
Microwave-Assisted Synthesis Of Cerium Doped Zno Nanostructures And Its Optical Properties
Authors: Shulga A. , Butusov L.A. , Chudinova G.K. , Sheshko T.F.
Published: April 2020

In this research we attempted to synthesize zinc oxide nanostructures doped with REE cerium by microwave-assisted method. The article presents the results obtained with different pH values of the processed solutions, the time of exposure to microwave irradiation, as well as the results of the application of cyclic irradiation exposure. Samples studied by fluorescence spectroscopy and scanning electron microscopy.
Hybrid silicon/phase-change metasurfaces and nanoantennas for active nanophotonics
Authors: Sinev I. , Ruiz de Galarreta C. , Trofimov P. , Alexeev A. , Bertolotti J. , Wright C. D.
Published: April 2020

All-dielectric metasurfaces and nanoantennas offer unprecedented flexibility and efficiency of manipulation of light at the nanoscale. Still, the functionality of conventional dielectric-based devices is fixed-by-design, i.e. the response is locked-in at the fabrication stage. To address the challenges offered by modern nanophotonics, active, dynamic and reconfigurable control of such structures is required. Here, we demonstrate active all-dielectric devices enabled by embedding subwavelength chalcogenide phase-change material inclusions in the volume of main silicon nanoresonators. We validate the concept via the design and development of a metasurface for active spectral filtering in the near infrared and a subwavelength nanoantenna providing complete switching of surface plasmon-polariton directivity pattern.
Applications of dielectric pads, novel materials and resonators in 1.5T and 3T MRI
Authors: Slobozhanyuk A. , Zivkovic I. , Shchelokova A. , Mikhailovskaya A. , Sushkov I. , Nenasheva E. , Melchakova I. , Belov P. , Webb A.
Published: April 2020

In order to boost the performance of magnetic resonance imaging without increasing the static magnetic field, it is necessary to increase its intrinsic sensitivity. This allows a reduction in the scanning time, increased spatial resolution, and can enable low-field strength systems (which are much cheaper and can be used to scan patients with metallic implants) to have a higher signal-to-noise ratio (SNR) so that they are comparable to more expensive higher field strength systems. In this contribution, we demonstrate radiofrequency field enhancing and shaping devices based on novel materials, such as high permittivity dielectric structures and metamaterials. These materials can substantially enhance SNR, thus potentially increasing image resolution or allowing faster examinations.
High directivity of the dielectric spherical antennas in 0.2-0.35 THz range
Authors: Storozhenko D V , Deev A V
Published: April 2020

The article presents the results of numerical simulation by the finite element method of a spherical dielectric resonator with a dipole antenna placed inside. The directional properties of this type of antenna in the 2–4 GHz and 0.2–0.35 THz bands are calculated. It is shown that in a narrow band due to high order Mie resonances, the peak directivity of the antenna can reach values of 12.5 dBi with radiation efficiency of 0.9 and a sphere size of the order of 1.2 λ. A variant of the antenna for the 0.2–0.35 THz range with its placement on a dielectric substrate is proposed, and the dimensional ratios of the structural elements for the narrow-band mode with maximum gain are presented.
Effect of Cu and Sn concentration on the performance of all-sprayed CZTS solar cell
Authors: Rajeshmon V.G , Vijayakumar K.P. , Sudha Kartha C.
Published: April 2020

Cu2ZnSnS4/In2S3 thin film solar cell was prepared using chemical spray pyrolysis. Influence of variation in copper concentration in precursor solution on the properties of CZTS thin films was monitored. Concentration of copper was found to have essential role in adjusting composition and crystallinity of CZTS thin films. Junction was fabricated using CZTS as absorber layer and spray pyrolysed In2S3 as buffer layer. Two sets of devices were prepared, one by varying copper concentration and the other by varying tin concentration in the precursor solution for the deposition of CZTS thin films. For both sets, In2S3 thin films were deposited as buffer layer and Ag electrodes were used for taking contacts. All the performance parameters were found to have dependence on the concentration of Cu and Sn. For getting maximum conversion efficiency, the sprayed CZTS absorber layer should have elemental ratio of Cu:Zn:Sn:S=2.5:1:0.7:12 in the precursor solution. Maximum efficiency obtained was 1.85 %.
Multipolar analysis of second-harmonic generation in (111) Gallium Arsenide nanoparticles
Authors: Volkovskaya I , Smirnova D , Xu L , Sautter J , Miroshnichenko A , Lysevych M , Camacho-Morales R , Kamali K Z , Karouta F , Vora K , Tan H H , Kauranen M , Staude I , Jagadish C , Neshev D , Rahmani M
Published: April 2020

We perform multipolar analysis of second-harmonic generation (SHG) from (111)-grown gallium arsenide (GaAs) nanoantennas and discuss its specifics. It was experimentally demonstrated that the conversion efficiency in axially-symmetric (111) GaAs nanoparticles remains constant under the polarization rotation of normally incident radiation in a wide range of particle sizes, while the SHG radiation pattern changes. We apply the analytical method based on the Lorentz lemma to explain this behaviour. The induced nonlinear current is decomposed into two rotating contributions, which are shown to generate multipoles of different parities. Thus, the total SHG intensity in the far-field is proved to be independent of the in-plane rotation of the pump polarization. Nevertheless, due to the threefold symmetry of the crystal with regard to the (111) direction, the SHG radiation pattern rotates around the polar axis repeating its shape every 60°.
Capabilities of ADDA code for nanophotonics
Authors: Yurkin M A , Smunev D A , Akhmetyanova A E , Glukhova S A
Published: April 2020

The open-source code ADDA is based on the discrete dipole approximation (DDA) – a numerically exact method derived from the frequency-domain volume-integral Maxwell equation. It can simulate interaction of electromagnetic fields (scattering and absorption) with finite 3D objects of arbitrary shape and composition. Besides standard sequential execution on CPU or GPU, ADDA can run on a multiprocessor distributed-memory system, parallelizing a single DDA calculation. This together with almost linear scaling of computational complexity with number of dipoles (discretization voxels) allows large system sizes and/or fine discretization levels. ADDA is written in C99 and is highly portable. It provides full control over the scattering geometry (particle morphology and orientation, incident beam) and allows one to calculate a wide variety of integral and angle-resolved quantities, including those related to point-dipole excitation. Moreover, ADDA can rigorously and efficiently account for plane homogeneous substrate near the particle, and employ rectangular-cuboid voxels. It also incorporates a range of state-of-the-art DDA improvements, increasing both the accuracy and computational speed of the method. At the conference we will describe the main features of current version of ADDA with special emphasis on nanoparticles and present several simulation examples.
High-value chemicals from marine diatoms: a biorefinery approach
Authors: Bayu A , Rachman A , Noerdjito D R , Putra M Y , Widayatno W B
Published: April 2020

Nowadays, we are going a step forward into the new era for the sustainable production of industrial commodity products such as energy, fine-chemicals, active compounds and materials from renewable biomass. Marine diatoms offer great potential as an untapped living factory for the generation of valuable commodity chemicals. As a photosynthetic microorganism, diatoms contain pigments, which have a high market value in the cosmetic, pharmaceutical and food colorant industries. Their unique metabolism to utilize the soluble silicate in seawater for their porous silica cell wall (frustule) opens an opportunity for the nano-porous material industry. Diatom’s lipids consist fatty acids, which could be catalytically upgraded into high-quality fuels like fatty acid alkyl esters (biodiesel) or hydrocarbons (green diesel). In the analysis reported here, we present the potential of biorefinery pathways of valuable components in marine diatoms. Understanding the biochemistry of them and the application of their valuable chemicals are discussed to gain insights for the opportunities and the key barriers in the development of marine diatoms-based biorefinery.
Utilization of various encapsulation methods in proteolytic bacteria to maintain biomass cells during storage
Authors: Sundari U Y , Noor E , Haditjaroko L , Permatasari I D , Rohadian A R
Published: April 2020

Bacterial isolates used are proteolytic bacteria. Bacterial cell encapsulation aimed to protect cells from some external environmental factors that can interfere with the metabolism of the cell, so as to maintain the viability of bacteria, extending the shelf life and facilitate the distribution and utilization. In this study, the encapsulation of the bacteria was carried out by nanoencapsulation method using a spray dyer and electrospun nanofibers. Encapsulation in nanosize has advantages such as immobilization efficiency because of the increased surface area and volume, providing protection due to the increased flexibility of the encapsulation material. Nanoencapsulation the proteolytic bacteria was using the coating material in the form of skim milk and maltodextrin. Electrospun nanofiber for proteolytic bacteria was using polyvinyl alcohol (PVA) and skim milk as a coating material. The results of the viability of proteolytic nanoencapsulation were higher when encapsulated using skim milk at a concentration of 15% was 44.07%. Results of encapsulation of bacteria using electrospun nanofiber method showed three parameters that affected the process of electrospun nanofiber: the coating material parameters (concentration, viscosity and mixing ratio), the process parameters (voltage, flow rate, and the distance between the collector and needle), and environmental parameters (relative humidity and temperature).
Target tracking based on neural network depth feature and texture fusion
Authors: Cao Yongzhan , Liu Meiju , Yang Shanykui , Yang Guodong , Chen Peng , Zhu Shuyun , Ge Zhuang , Liu Yuwang
Published: April 2020

This paper presents a method of target tracking based on convolution neural network and texture feature fusion. The lower layer of the convolutional neural network can extract some spatial structure, shape and other features of the target. High-level level can extract relatively abstract semantic information. In this paper, vgg-m convolutional neural network is adopted to realize tracking by adaptive fusion of the extracted depth features of Conv2 and Conv5 with the texture features extracted by two-dimensional Gabor filtering. In this paper, the experimental analysis of this method is carried out on the OTB2013 data set, and the results show that this method can achieve more accurate positioning of the target and has a strong timeliness.
The technology of picking up the first break of surface microseismic based on constraint
Authors: Liu Liting , Kang Liang , Tan Xing , Tang Yong , Liao Jihao
Published: April 2020

In this paper, a constraint based first break acquisition technique for surface monitoring is proposed. This method enables users to automatically pick up the starting point and the ending point of the first arrival position after simply observing the starting point and the ending point of the first arrival position and determining the position. Secondly, because the first break automatic picking method mentioned in this paper will analyze the data characteristics of each channel carefully to find the first break time point in each channel accurately, so that the accuracy of first break picking is significantly improved.
Depth of Moho surface in the central Sichuan region revealed by deep earthquake exploration
Authors: Chen Yu , Yang Zhichao , Liu Wei
Published: April 2020

Deep seismic reflection technology has been recognized by the international geosciences as an effective technical means to detect the fine structure of the lithosphere and solve the deep geological problems. Since the 1970s, a large number of deep seismic reflection profiles have been collected in the Sichuan Basin and the periphery, providing a basis for deep research and seismic acquisition techniques for crustal structure research in the region. Because the deep reflection seismic method has the characteristics of large detection depth, high resolution, accuracy and reliability, deep reflection seismic technology is still the main means of deep crust fine structure research in the future. In this paper, the ultra-deep seismic data is collected to reveal the geological characteristics of the Moho surface in the Sichuan Basin in the Sichuan Basin, which is stable and shallow and has a depth of about 45 km.
Calculation of Beam Hardening in Industrial X-ray Computed Tomography and its Correction using Filtration and Linearization Methods
Authors: Ahmed O. M. H. , Song YuShou , Xie Zhaoyang , Ayoub ANUOR A.T.
Published: April 2020

X-ray computed tomography is becoming an instrument for quality assurance as nondestructive testing for product inspection in industrial applications. However, the systematic error in the XCT image resulting from the physical processes of image reconstruction must be corrected. Beam hardening is one of the major artefacts that come due to an extensive range of photon energies in common x-ray sources in computed tomography instrument so-known polychromatic X-rays. The polychromatic can cause a nonlinear relationship between the attenuation and the thickness. As a result, the reconstructed image seems to have some darkness in the centre, which is considered a significant decreasing of the image quality. In this work the calculations of beam hardening and its correction using filtration and linearization methods were described. The calculations were done in four stages: the GEANT4 code was used for spectrum simulation; an optimum filter materials and thickness was chosen by a mean energy ratio method; the attenuation of aluminium material was numerically calculated using the basic polychromatic attenuation formulas, and the beam hardening was corrected using linearization and compared with the filtration method. The calculated polychromatic attenuations results of aluminium were found to be in good agreement with the existing literature. The linearization correction offers better beam hardening correction which gave a good linearity estimation without changing SNR when compared with the pre-filtration method.
The Factors Affecting Intention to Internal Whistleblowing: An Idea of Free Cheating Environment
Authors: Hardi  , Wiguna Meilda , Mela Nanda Fito
Published: April 2020

The main problems of this study are as follows: Does locus of control affect the intention to perform internal whistleblowing? Does the degree of seriousness of fraud affect the intention to conduct internal whistleblowing? Does Reward affect the intention to do internal whistleblowing? The data obtained in this study by distributing questionnaires to the respondents, i.e., staff/employees of OPD District Siak, Rokan Hilir and Kuantan Singingi regency with the total of 337 respondents. Data analysis with multiple linear regressions is used to obtain a comprehensive picture of the effect of independent variables namely locus of control, seriousness of fraud, and reward to the dependent variable is intense to conduct internal whistleblowing. The results showed that: locus of control effect on internal whistleblowing. The higher a person's locus of control level the higher they are to perform internal whistleblowing. The degree of seriousness fraud affects internal whistleblowing. The higher the level of fraud that occurs in the agency where staff/employees work the higher they are to conduct internal whistleblowing. The reward also influences internal whistleblowing. The higher the reward will be received by the whistle-blower the higher they are to do the internal whistleblowing.
The Impact of Government Policies towards the Economy and Education of Fishermen’s Children in Padang City
Authors: Eriyanti Fitri , Engkizar  , Alhadi Zikri , Moeis Isnarmi , Murniyetti  , Yulastri Asmar , Syafril Syafrimen
Published: April 2020

This study aimed at analyzing the impact of government policies towards the economy and education of fishermen's children of Minangkabau and Nias ethnics in Padang City. This study used the qualitative method with a case study approach. The main data sources were gathered from structured interview to eight fisherman families and were analyzed thematically using NVivo 10 software as the qualitative analysis instrument. The result of the study discussed four essential themes namely; first, the government policies towards the fisherman had been capable of improving their economy both Minangkabau and Nias ethnics. Second, the economic improvement for Minangkabau ethnics had an impact towards their life proven by the increasing quality of their children's education from the primary level until the higher education level. Third, the economic improvement for Nias ethnics, on the other hand, had no impact at all towards their children's education quality. Fourth, the impact differences regarding the children's education of both ethnics were caused by culture, parents' mindset, and children's' interest in education. According to parents and fishermen’s children of Minangkabau ethnic, education matters a lot for the sake of pursuing a brighter future, while according to parents and fishermen’s children of Nias ethnic, education does not really matter.
The Concept of Unen-Unen and Free Corruption Environment: An Anti-corruption Lesson from Javanese Heritage
Authors: Sariningsih Melinda , Widhyasmaramurti
Published: April 2020

Corruption is generally attached to one’s position to obtain personal gain and create disharmony in the community. The corruption in Indonesia somehow transforms into a detrimental problem nowadays. Therefore, this study aims at proposing an alternative concept of anticorruption from a Javanese cultural heritage which passed down from generation to generation. This anti-corruption concept formed into a variety or expression which is called unen-unen. It well known delivered from trans-generation by understanding the meaning of Unen-unen. This study record and explores Unen-unen from the book 1001 Pitutur Luhur Budaya Jawa (Ari, W. and Gunawan, W. 2014). The selection of Unen-unen was found contains the concept of anticorruption. It then analyzed using a qualitative approach using the Triangle Theory of Meanings of Odgen and Ricahrds (1952), and the Kohlberg (1995) Moral Development Theory. The analysis of this study reveals Unen-Unen has a unique concept of anti-corruption that can be used to teach a moral lesson from the early age to adults. It somehow ranges from phases pra-conventional to post-conventional as efforts to prevent the corruption.