Sergei Khakhomov

Francisk Skorina Gomel State University, Gomel, Belarus · Optics

The quasi-ring Airy vortex beam (QRAVB) is a special type of vortex beam that has been proposed recently, which performs efficiently in turbulent links. The bulky optical elements such as the space light modulator used for developing the QRAVB hinder their applications in modern integrated optical communication devices. Hence, we propose a type of...

The purpose of this work is to build the analytical model of the behavior of a harmonic wave in a nonlinear optical medium with periodically arranged nanofilms. Methods. The modernized method is presented of non-smooth transformation of the argument to eliminate the Dirac functions on the right side of the non-linear inhomogeneous differential equa...

In this article, the structural stability of a metasurface absorber that works at 2.8 THz is analyzed. Since the absorber is made of metallic titanium, its elemental inclusions will be heated up and expand when absorbing electromagnetic waves. To evaluate the accumulated heat, the structural thermal expansion and the stability of the wave-absorbing...

In this work, we have investigated the photocurrent and spectral sensitivity of the silicon/SrTiO3:xNb/perovskite structures. The sol–gel method carried out the deposition of undoped SrTiO3 layers as well as niobium-doped (SrTiO3:Nb) layers at atomic concentrations of 3 and 6% Nb. The perovskite layer, CH3NH3PbI3−xClx, has been deposited by the vac...

The DNA molecule is considered as an object of nature-like technologies, with the focus on the special electromagnetic properties of DNA-like helices. This is the difference from the traditional approach to the DNA molecule as the repository of genetic information. DNA-like helices are regarded as artificial micro-resonators, or “meta-atoms,” exhib...

We use Hypergeometric Gaussian-II (HyGG-II) modes to investigate the impacts of non-Kolmogorov atmospheric turbulence on the Holevo channel capacity of a quantum communication scheme. The capacity of HyGG-II modes can be higher than that of Laguerre-Gaussian modes via modulating the hollowness parameter. The influences of low-order turbulence aberr...

Topological charge (TC) is generally acknowledged as an important attribute of an optical vortex (OV), which indicates the twisted characterization of the wavefront. In most circumstances, the TC remains constant as an integer or fraction along the azimuthal direction. Herein, by transforming the TCs into the trigonometric functions of the azimutha...

The diffraction limit of light due to the loss of evanescent waves that carry high spatial frequency information in the far field restricts the practical applications of terahertz imaging technology. In order to break the diffraction limit, we investigate the super-resolution capability of different types of multilayered graphene-dielectric hyperbo...

Fano resonance is based on plasmonic metasurfaces and has many applications in all kinds of fields. In this paper, we propose an independently switchable double-layer raster structure based on graphene. Depending on the highly adjustable nature of graphene, the Fermi energy level can be adjusted to control the Fano resonance at different wavelength...

The possibility of using a conducting double DNA-like helix as the basis of an electromagnetic wave polarizer, which converts an incident linearly polarized wave into a reflected wave with circular polarization, has been shown. A high-frequency resonance is studied, at which the wavelength of the incident radiation is approximately equal to the len...

Fano resonance is based on plasmonic metasurfaces and has many applications in all kinds of fields. In this paper, we propose an independently switchable double-layer raster structure based on graphene. Depending on the highly adjustable nature of graphene, the Fermi energy level can be adjusted to control the Fano resonance at different wavelength...

The design and modeling of a metasurface is carried out, which makes it possible to transform an incident linearly polarized electromagnetic wave into a transmitted wave with elliptical polarization close to circular. At the same time, the reflection coefficient of the wave is close to zero at the resonant frequency, since the metasurface is simila...

The present work presents the results of the investigation of multiferroic materials (BiFeO3 and Bi1-xSmXFeO3) with perovskite structure, which possesses two types of orderings: ferromagnetic and ferroelectric. Also, the obtained samples were investigated by Raman spectroscopy to provide detailed information about chemical structure, phase purity a...

We present a hybrid Tamm system targeting the tunable multichannel absorber. The proposed optical absorber is analyzed and investigated by using the transfer matrix method (TMM). The numerical and theoretical studies show that the four perfect absorption peaks are generated by two types of resonant modes excited in the structure, which can be reaso...

The work aims to produce and experimentally study an absorbing and at the same time weakly reflecting metamaterial consisting of conducting planar two-turn spirals on a dielectric substrate. Such a pre-designed metamaterial is manufactured within the framework of printed circuit board technologies.KeywordsPlanar spiralsMicrowave rangeMetamaterial

This paper presents ultrathin multi-focusing metalenses that can produce several independent focusing spots, useful in imaging for light flow redistribution, even asymmetrical into many focal spots. The proposed design includes quadrangular frustum pyramids serving as individually tuned nanoantennas; their structure can be modified, facilitating wa...

In recent years, the research on tunable and high-performance terahertz devices has attracted widespread attention. In this paper,we propose a novel refractive index sensor consisting of monolayer graphene and multilayer photonic crystal with a defect layer. It is found that Tamm plasmon polaritons can be excited at the top graphene interface, whic...

We present a hybrid Tamm system targeting the tunable multichannel absorber. The proposed optical absorber is analyzed and investigated by using the transfer matrix method (TMM). The numerical and theoretical studies show that the four perfect absorption peaks are generated by two types of resonant modes excited in the structure, which can be reaso...

Pure BiFeO3 (BFO) and doped Bi0.9La0.1FeO3 (BLFO) thin films were prepared on Pt/TiO2/SiO2/Si substrates by a modified sol–gel technique using a separate hydrolysis procedure. The effects of final crystallization temperature and La doping on the phase structure, film morphology, and nanoscale piezoelectric properties were investigated. La doping an...

In this work, we investigate the possibilities of reaching wide-angle perfect absorption with Huygens' metasurfaces possessing both electric and magnetic responses. We analyze the role of the anisotropy of the polarizability tensor of the unit cell and reveal the conditions for the optimal angular stability in symmetric absorption as well as polari...

We present a tunable multichannel absorbers in a hybird optical Tamm system at near-infrared frequencies. The simulation results reveal the structure capable of exciting four perfect absorption peaks, which are generated by two types of resonance, namely a guide-mode resonance (GMR) in a graphene-based grating and optical resonance induced by Tamm...

Graphene-based hyperbolic metamaterials are well known for their optical anisotropy, high absorption of electromagnetic radiation, and low energy loss. We proposed a novel multilayer graphene-silica hyperbolic metamaterial designed as a grating structure providing narrowband near-perfect absorption of radiation in a mid-infrared band. The absorber...

The original version of this article unfortunately contained a mistake.

In this paper we study electromagnetic forces induced on DNA and DNA-like helices by external electromagnetic waves. We consider simultaneously occurring forces and torques, interconnected and acting along the double helix axis. Since the DNA molecule has an absorption band in the ultraviolet and visible range near wavelengths = 280 nm and = 500 nm...

In the article the metamaterials and metasurfaces which consist of metal helices and omega elements of classical or rectangular types are considered. It is analyzed the similarities and differences between metamaterials and crystals.

In this paper, we propose a tunable coordinated multi-band absorber that combines graphene with metal-dielectric-metal structures for the realization of multiple toward perfect absorption. The parametric inversion method is used to extract the equivalent impedance and explain the phenomena of multiple-peak absorption. With the change of the Fermi l...

The paper aimed to study the interaction of the THz range electromagnetic waves with metamaterials, consisting of rectangular omega elements, as well as to develop a one-sided and double-sided “ideal” THz wave absorber based on such structures.

The sensors with multifold nanorod metasurfaces array based on hyperbolic metamaterials with a multi-film structure are proposed in this paper. The Fano-like effect is analyzed to explain the coupling between different hyperbolic metamaterials structures. The sensors can be improved not only by changing the structure parameters, but also by changin...

In this paper a double DNA-like helix as a promising element of metamaterials, metasurfaces and antenna systems for various frequency ranges is considered. The article demonstrates the possibility of creating the required radiation pattern of such a helix, excited by a plane electromagnetic wave by changing its angle of incidence. It is shown, that...

The paper aims to create a new type of polarizers in the THz range of electromagnetic waves, comprising an array of micro-dimensional planar rectangular omega elements. The metal omega elements under consideration have a well-balanced shape, since the incident electromagnetic wave induces in them an electric dipole moment and a magnetic moment, whi...

The paper describes the sol-gel method for producing photocatalytic materials based on titanium oxide. The temperature-time regimes of heat treatment of the obtained materials are determined. The surface properties of the resulting coatings were studied by scanning electron microscopy and asthmatic force microscopy. The photocatalytic properties of...

The present work aims to design and study novel functional materials with multiferroic properties required in electric applications, such as magnetic and magnetoresistive sensors, actuators, microwave electronic devices, phase shifters, mechanical actuators etc. Complex oxides BiFeO3 and Bi0,9La0,1FeO3 for analysis of its structural properties were...

A double DNA-like helix in which two strands are mutually displaced along a common axis is considered. A high-frequency resonance is investigated, at which the wavelength of the incident radiation is approximately equal to the length of a helix turn. All three components of the electric force and magnetic force acting on an arbitrary element of one...

In this paper a double DNA-like helix as a promising element of metamaterials, metasurfaces and antenna systems for various frequency ranges is considered. The article demonstrates the possibility of creating the required radiation pattern of such a helix, excited by a plane electromagnetic wave by changing its angle of incidence. It is shown, that...

In this paper, we propose a tunable, multi-band, selective absorber composed of multiple layers. Each layer consisted of SiO2/graphene/SiC, and a layer of silver was used as the ground plane of the entire structure. Simulation results show that we can passively and actively coordinate the resonant frequency of the perfect absorption peak by changin...

In this paper, we theoretically and numerically demonstrate a dual-band independently adjustable absorber comprising an array of stacked molybdenum disulfide (MoS2) coaxial nanodisks and a gold reflector that are separated by two dielectric insulating layers. The array plane functionality is explained by the dipole resonances with the MoS2 nanodisk...

In this research, the features of electro-induced periodical structures in the volume of LiTaO 3 thin plate were theoretically and experimentally investigated. For the theoretical and experimental investigations, the calculations based on the finite element method and measuring of the surface acoustic wave (SAW) interaction were implemented simulta...

The present work aims to design and study novel functional materials with multiferroic properties required in electric applications, such as magnetic and magnetoresistive sensors, actuators, microwave electronic devices, phase shifters, mechanical actuators etc. Complex oxides BiFeO 3 for analysis of its magnetic properties were synthesized by sol-...

The objective of the paper is to create on the basis of omega-shaped bianisotropic elements new absorbing metamaterials and coatings that do not have a reflecting base and are “invisible” on the irradiated side.

The great problem for ferroelectric capacitors is the physico-chemical and mechanical interaction of ferroelectric films with surrounding materials, which leads to degrading of the characteristics of the ferroelectric element, increasing of current leakage and degradation of the transistor structures. Nanostructured ferroelectric films with the gen...

The objective of the paper is creating wide-band polarization transformers consisting of two-dimensional regular array of omega-elements on the substrate, which show resonance-frequency behavior in THz frequency range.

Here we present theoretical results for estimation of electromagnetic field energy density and absorbed energy in dispersive lossy chiral single-component metamaterials which consist of an ensemble of identical helical resonators as inclusions. The shape of the helical resonator can vary over a wide range, from a straight wire to a flat split ring....

A twist polarizer metasurface for polarization rotation by an angle of 90° is proposed and realized at microwave frequencies. The metasurface consists of sub-wavelength metallic helices arranged periodically in a single layer and operates in transmission geometry with a nearly unity cross-polarization conversion coefficient at resonance. The struct...

The properties of an artificial anisotropic structure composed of omega-elements are numerically simulated. Analytical expressions for the dielectric, magnetic and magnetoelectric susceptibilities of the structure are derived. The frequency dependence of the effective parameters of a metamaterial has been determined taking into account trajectories...

In the present paper, a theoretical and experimental study of a highly absorptive, weakly reflective coating designed and fabricated on the basis of 3D THz resonant elements is reported. Transmission and reflection of electromagnetic waves from the metamaterial-substrate structure involving a highly absorptive, weakly reflective array of artificial...

Method of chemical-mechanical polishing (CMP) approach to production submicron and deep submicron levels. For monocrystalline silicon wafer by CMP, we have developed a suspension, containing solid phase, amorphous, spherical particles of nanosized aerosil. SiO2 particles are homogenously distribute in an alkaline medium. Removing material in CMP is...

One of the urgent problems of modern engineering is to obtain a ferroelectric capacitor for various structures. A promising material in the class of ferroelectrics with perovskite structure is strontium bismuth tantalate-niobate SrxBiyNbzTa2?zO9 (SBTN). The synthesized layers should be homogeneous on structure and thickness, to have good fatigue ch...

In the present article, we study the long bifilar helix in which electric currents are quasi-stationary, i.e. the wavelength of the electromagnetic field is much longer than the turn of the helix. All components of the force acting on a physically small element of one helix from the other helix having a big length are calculated. The case when the...

Energy of propagating electromagnetic waves can be fully absorbed in a thin lossy layer, but only in a narrow frequency band, as follows from the causality principle. On the other hand, it appears that there are no fundamental limitations on broadband matching of thin resonant absorbing layers. However, known thin absorbers produce significant refl...

In the present paper, we study electromagnetic properties of single-turn, double-turn and DNA-like helices in microwave range. In particular, we determine the magnetic flux density in the center of the inclusions and their inductance and capacitance. In this paper we have numerically obtained the magnetic field of different kinds of helices: the si...

The electrically thin absorber of electromagnetic waves is under study. We proposed a new concept of the perfect absorber which consists from a single layer of the smooth double-turn helices. This allows one to design an absorber with unprecedentedly small thickness. Simple and smooth shape of the helices makes them more preferable from experimenta...

We present a new ultrathin metamaterial that acts as a frequency-selective absorber of terahertz radiation. The absorber is a square array of pairs of omega-shaped micro-resonators made of high-ohmic-loss metal. The metamaterial provides significant suppression of transmitted and reflected radiation in a bidirectional regime (that is, for both forw...

This article describes some of the paths through which electromagnetics research of complex media and metamaterials has reached the present active state. In particular, events of a period in 1990s will be illuminated during which new scientific contacts between Former Soviet Union and the West were established. The series of chiral and bianisotropi...

The properties of an artificial anisotropic structure formed by microhelices have been numerically simulated by the example of a specially designed sample. The sample contains paired helices with right- and left-handed twisting directions, due to which the metamaterial chirality is compensated for. Helices are characterized by precalculated optimal...

We realized and experimentally tested a conceptually new kind of electrically thin absorbers of electromagnetic waves. The idea is to utilize a single layer of precisely designed meta-atoms. This allows one to design an absorber with unprecedentedly small thickness. The absorber implies absence of a ground plane. High efficiency of the realized str...

In this work, we consider potential energy of recently conceptualized optimal (balanced) bianisotropic particles in electromagnetic fields. The case of non-resonant lossless particles is studied. Knowing the potential energy of optimal bianisotropic particles in the fields of the respective excitations, we find the acting force on the particle in i...

Uniaxial electrically thin layers formed by arrays of smooth helices are under study. Simple and smooth shape of the helices makes them more preferable from experimental point of view in comparison to other chiral particles. Here we optimize by simulation mutual orientation and density of the helices in the array so that it acts as a twist-polarize...

In this article we study scattering of plane electromagnetic waves by a metal cylinder surrounded by straight copper wires. Possibility to achieve partial recovery of the wave front behind the cylinder is demonstrated with certain parameters of the wires and their location in the structure. Reconstruction of the wave front is observed in frequency...

The chiral properties of an artificial anisotropic structure composed of microhelices are numerically simulated using the example of a sample developed by a team of authors from the Institute of Semiconductor Physics of the Russian Academy of Sciences. It is shown that this artificial structure can exhibit strong chiral properties in the THz range....

Study of polarization properties of DNA was chosen as one of primarily important inconnection with asymmetry of the shape of DNA. The preliminary theoretical calculation showed that the shape of DNA is optimal for formation of a circularly polarized electromagnetic wave under the assumption of resonance (~ 10 nm). The experimental study conducted a...

Currently, 2D and 3D structures of different symmetries can be formed from DNA molecules. The electromagnetic properties of this new natural chiral material can be changed by metalizing DNA. Spatial structures of this type can be used in nanotechnology to prepare metamaterials for the far-UV region. It is shown by the example of an octahedron and a...

The optimum form of a long helical molecule, which DNA is, has been calculated in terms of the classical electromagnetic theory. Three different methods of classical electrodynamics are used: the theory of dipole radiation of electromagnetic waves, the energetic power approach, and a helical model of molecules of chiral medium. In all three cases,...

In this paper we study helical inclusions of a certain shape (called the “optimal shape”), such that the electric, magnetic, and magneto-electric polarizabilities are equal, and discuss unusual reflection properties of artificial materials based on such inclusions. We study helical particles with optimized design parameters, which can make the real...

In this article we study helical inclusions of a certain shape (called the “optimal shape”), such that the electric, magnetic, and magneto-electric polarizabilities are equal, and discuss unusual refractive and absorptive properties of artificial chiral materials based on such inclusions. We propose a new method of analytical calculation of resonan...

The possibility of linearly polarized electromagnetic microwave conversion into a circularly polarized wave using single-turn helices with preliminary calculated optimal parameters is demonstrated. The helices are characterized by equal dielectric, magnetic, and chiral susceptibilities. Such optimal helices can be further used