Перегляд за автором "Stognii, N. P."
Зараз показано 1 - 20 з 35
Результатів на сторінку
Варіанти сортування
Публікація Accurate investigation of coupled plasmonic resonances in a chain of silver nanowires(IEEE, 2016) Stognii, N. P.; Sakhnenko, N. K.This paper presents investigation of plasmonic properties of coupled metal nanowires arranged to form a finite linear chain. Coupled plasmon resonances of such structures embedded into dielectrics with different dielectric permittivity are studied. The main goals of the paper are to validate true potential of a plasmon nanowire-based structure in sensing applications and to reveal optimized configurations with narrowband plasmonic resonances and enhanced sensitivity.Публікація Bonding and antibonding combinations of plasmons in aggregates of plasma columns(IEEE, 2012) Stognii, N. P.; Sakhnenko, N. K.Theoretical investigation of the plasmonic resonances of coupled cylindrical plasma columns is presented. Mechanism of plasmonic mode coupling in a pair of coupled plasma columns and in a cluster with square configuration that can be considered as bonding and antibonding combinations of isolated column plasmons is investigatedПублікація ‘Bright’ and ‘dark’ plasmons in the systems of metal nanowires(IRE, 2014) Stognii, N. P.; Sakhnenko, N. K.Many authors find SPs by investigating resonance peaks in Scattering Cross Section (SCS). This study cannot be considered as a complete one, because in this way only ‘bright’ plasmons can be seen, ’dark’ plasmons that do not couple efficiently to incident wave cannot be discovered in such a description. We developed nonquasistatical expressions for the eigenvalues of SPs that includes finding of eigenfrequencies and Q-factor. Using this approach all possible SPs can be found and investigated, including ‘dark’ and multipole ones.Публікація Coupled plasma cylindrical columns as sub-wavelength antenna(КПИ, 2011) Stognii, N. P.; Sakhnenko, N. K.We theoretically study the resonant properties of an aggregate of coupled cylinders filled with negative permittivity plasma. Such a problem has applications in optical and plasma antennas, intelligent antenna systems, and pulse-driven antenna arrays. Chain of columns of plasma can be used in the design of both transmitting and receiving antennas with a very broad frequency range and tunability that allows switching it on and off very fast. The Mie series expansion is used to derive the solution. Electromagnetic analysis of the spectrum of different plasmon resonances is presented.Публікація Coupled plasmon hybrid modes in aggregates of metal nanowires(IEEE, 2015) Stognii, N. P.; Sakhnenko, N. K.Investigation of the plasmonic resonances in aggregates of metal nanowires is presented. Mechanism of plasmonic mode coupling in a system of metal wires that can be considered as hybridization combinations of isolated wire plasmons is investigated.Публікація Eigenvalue problem in a linear chain of coupled infinite-long plasma cylinders(IRE, 2011) Stognii, N. P.; Sakhnenko, N. K.Strong interest in the electromagnetic wave propagation and scattering in the presence of plasma objects is due to the wide range of potential applications of such study. Tuning of resonant characteristics of resonators by free carrier plasma injections can be used in active switches or tunable filters. Transient phenomena in plasma lead to the possibility of the frequency upshifting and the generation of waves. Using resonators composed of negative permittivity materials such as plasma can form the basis of effective small-size antenna elements. The main goal of this paper is to analyze the plasmonic resonances in finite array of plasma coupled cylinders.Публікація Excitation of plasmon resonances on nanowire and nanoshell by complex source point(IEEE, 2016) Stognii, N. P.; Sakhnenko, N. K.Transient pulsed excitation of the localized surface plasmons on nanowire and nanoshell is visualized and analyzed. The complex source point concept is used to simulate an incident transient beam. Rigorous mathematical method based on the Laplace transformation is applied. Time domain field representation is obtained through the evaluation of the residues at singular points associated with the eigenvalues of the structure and integrals along the branch-cuts on the complex plane.Публікація Excitation of surface plasmons by localized transient sources(IEEE, 2016) Stognii, N. P.; Sakhnenko, N. K.Theoretically investigate the excitation of plasmon resonances of metallic nanowires and nanoshell by external transient pulses is presented. To solve the problem, we used a accurate mathematical approach based on the Laplace transform, which allowed us to obtain an analytic representation of the solution. Finding the inverse transformation is based on the assessment of residues at singular points that correspond to the plasmon resonances of our structures.Публікація Fractional-rational representation of the frequency spectrum of the scattered field for a Drude-metal nanowire resonating on localized surface plasmons(IEEE, 2017) Andreev, M. V.; Drobakhin, O. O.; Stognii, N. P.; Sakhnenko, N. K.The paper discusses the problem of determining the eigenfrequencies of surface plasmons for metal nanowire over the frequency spectrum of the scattered field. To determine the eigenfrequencies a fractional-rational approximation of the frequency spectrum based on continued fractions was used. Q-factors for lower and higher modes of the localized surface plasmons are investigated.Публікація Hybrid plasmons in assemblies of coupled metal nanowires(IEEE, 2014) Stognii, N. P.; Sakhnenko, N. K.This paper presents an accurate study of plasmon hybridization in assemblies of coupled metal nanowires. Our modeling provides results in terms of eigenfrequencies and quality factors. For this eigenvalue problem that follows from Maxwell’s equations has been solved. Possibility of quality factor enhancement in optimized assemble configurations has been demonstrated.Публікація Hybridization of plasmons in coupled nanowires(IEEE, 2012) Sakhnenko, N. K.; Stognii, N. P.Theoretical study of plasmon resonant eigenfrequencies in metal nanowires is presented. Mechanism of the plasmonic mode coupling that can be considered as symmetric and antisymmetric combinations of isolated wires plasmons is investigated. Accurate analysis of the spectrum of different plasmon resonances is presented.Публікація Influence of the environment on the coupled metal nanowire plasmon resonances(IRE, 2013) Stognii, N. P.; Sakhnenko, N. K.In this paper we consider the plasmon resonances of single metal nanowire and coupled nanowires embedded in dielectric media with different values of permittivity. Enhancement in sensitivity to environment properties is observable in the cluster with square configurationПублікація Integral transforms and the regularisation method in the time-domain excitation of open PEC slotted cone scatterers(IET Microwaves, Antennas and Propagation, 2021) Doroshenko, V. O.; Stognii, N. P.An initial‐boundary value problem for the transient electromagnetic field in the presence of a complicated‐shape scatterer is studied. The considered biconical zero‐thickness and perfectly conducting surface with periodic longitudinal slots has many special cases, each of which is of separate practical interest. A new analytical‐numerical technique is presented that is based on the Mehler–Fock integral transform and the method of analytical regularisation. The source of excitation of the slotted bicone is a radial electric dipole with an arbitrary time dependence on the field. The proposed method makes it possible to obtain an analytical and numerical solution of the problem to carry out a qualitative and numerical analysis, and to study the characteristic features of the main scattering. Due to the use of the method, the initial‐boundary value problem is reduced to a Fredholm type of the second kind system of linear algebraic equations (SLAE‐2). The dependences of the condition number on the problem parameters and the estimation of the SLAE‐2 convergence with larger truncation orders are given. The far‐field radiation patterns are plotted for various values of the problem parameters, the behaviour of the near field at the apex of the slotted cone is studied, and the regime of the slot wave propagation is analysedПублікація Investigation of plasmonic properties of coupled metal wires in the cluster with triangular or square configuration(IEEE, 2014) Stognii, N. P.; Sakhnenko, N. K.This paper presents a theoretical investigation and a straightforward analysis of the plasmonic properties of coupled metal wires in the cluster with triangular or square configuration. Solution of the eigenvalue problem in form of matrix equations is received. Eigenoscillationg frequencies and quality factors of the nanowires of such configurations are studied. Possibility of quality factor enhancement in optimized assemble configurations has been demonstratedПублікація Mathematical Modeling of Radiation from a Periodical Multiple-Slot Superwide Antenna(2023) Doroshenko, V. O.; Stognii, N. P.Results of studying a model boundary value electromagnetic problem for a conical multi-element periodic structure in a rigorous formulation are presented. The problem solution method is based on using integral transformations and singular integral equations for the density of the induced surface current. The field distribution patterns in the wave zone are given in the case of exciting a cone with a longitudinal slot by pointed sources.Публікація Mathematical Modeling of the Radiation of a Conical Multiple-Element Antenna(2022) Doroshenko, V. O.; Stognii, N. P.The results of studying a model strict formulation problem of electric radial dipole excitation of a conical periodic multi-element structure are presented. It is shown that the solution of the considered problem is equivalent to the solution of the singular integral equation with a logarithmic singularity. Field distribution patterns and curves of the surface current density are given.Публікація Mathematical Modelling of Impulse Excitation of a Superwideband PEC Cone Antenna(2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers, CAOL*2019, 2019) Doroshenko, V. O.; Klimova, N. P.; Stognii, N. P.; Kostyn, Yu. D.The method for solving initial-boundary electromagnetic problems is proposed. It uses the Green’s function method and the Laplace and Meler-Fock integral transforms in a time domain. The model problem of special slotted cone antenna excitation is studied. Integral and series representation of electromagnetic field component are given.Публікація Modeling of Exiting Special Conical Multiple-Slot Srtucture(2022) Doroshenko, V. O.; Stognii, N. P.As a result of the studies of the model problem considered, it is shown that the problem of axisymmetric electric radial dipole excitation of a conical open structure, on the period of which there are conical strips and slots of different angular widths, is reduced to solving a singular integral equation with a logarithmic kernel. Based on the SIE numerical solution obtained in the case of one slot per period, a field distribution diagram depending on the angular width of the slot is given.Публікація Modeling the Electromagnetic Wave Diffraction on Conical Gratings Consisting of Zero-Thickness PEC Strips(2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers, CAOL*2019, 2019) Doroshenko, V. O.; Klimova, N. P.; Stognii, N. P.; Sova, G. V.The periodic gratings are effectively used for producing modern electronics and radio engineering equipment and complexes. The electromagnetic wave diffraction problem for cone gratings is considered. Impedance boundary conditions at cone structure are proposed. The problem of electromagnetic wave diffraction on cone gratings with imperfectly conducting strips is studied. Diagrams of electromagnetic field distribution are givenПублікація Modelling of transient plasmons dynamics in metallic cylinders(IEEE, 2012) Sakhnenko, N. K.; Chipouline, A.; Nerukh, A. G.; Stognii, N. P.; Pertsch, T.Transient pulsed beam excitation of the surface plasmon polaritons in metallic cylinder and hypothetical cylinder having both negative real parts permittivity and permeability is visualized and analyzed. The complex source point concept is used to simulate an incident transient beam. Rigorous mathematical method based on the Laplace transformation has been applied. Time domain field representation is obtained through the evaluation of the residues at singular points associated with the eigenvalues of the structure and integrals along the branch-cuts of a complex plane.