A. A. Kovalev
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View article: Spin-orbit conversion at the sharp focus of a circularly polarized light beam
Spin-orbit conversion at the sharp focus of a circularly polarized light beam Open
It is known that when tightly focusing a circularly polarized optical vortex, spin-to-orbital angular momentum conversion occurs. It is usually said that the longitudinal component of the spin angular momentum (SAM) vector is transformed i…
View article: Spin and orbital Hall effects in the tight focus of coaxial superposition of two cylindrical vector beams of different-parity orders
Spin and orbital Hall effects in the tight focus of coaxial superposition of two cylindrical vector beams of different-parity orders Open
We study tight focusing of coaxial superposition of two cylindrical vector beams (CVB) of different orders. In the initial plane, the polarization singularity index of such superposition equals the half-sum of the orders of the two constit…
View article: Detection of elliptical polarization parameters using a metalens
Detection of elliptical polarization parameters using a metalens Open
A metalens capable of detecting the polarization ellipticity of an incident beam is considered in this paper. This metalens consists of blocks with diffraction gratings of a 140-nm height and a 220-nm period. The metalens operates as a pol…
View article: Transverse and Longitudinal Energy Flows in a Sharp Focus of Vortex and Cylindrical Vector Beams
Transverse and Longitudinal Energy Flows in a Sharp Focus of Vortex and Cylindrical Vector Beams Open
It is shown in this work that, with strong focusing of a beam with optical vortex and circular polarization, three energy flows take place in the focal plane: direct longitudinal, reverse longitudinal and azimuthal transverse flows. Calcul…
View article: Nonreciprocal superfluidlike topological spin transport
Nonreciprocal superfluidlike topological spin transport Open
We study superfluidlike spin transport facilitated by thermal diffusion of magnetic domain walls, where the positive and negative chiralities of domain walls act as opposite topological charges. The topological charge conservation leads to…
View article: Determination of Norms of Recreational Physical Activity on the Basis of Ranking Analysis
Determination of Norms of Recreational Physical Activity on the Basis of Ranking Analysis Open
The author considers the methodology of determining the norms of physical activity of recreational physical training practitioners on the basis of rank analysis. For determination of personalized norms of physical activity it is proposed t…
View article: Room Temperature Magnetic Skyrmions in Gradient-Composition Engineered CoPt Single Layers
Room Temperature Magnetic Skyrmions in Gradient-Composition Engineered CoPt Single Layers Open
Topologically protected magnetic skyrmions in magnetic materials are stabilized by interfacial or bulk Dzyaloshinskii-Moriya interaction (DMI). Interfacial DMI decays with increase of the magnetic layer thickness in just a few nanometers a…
View article: Polarization Strips in the Focus of a Generalized Poincaré Beam
Polarization Strips in the Focus of a Generalized Poincaré Beam Open
We analyze the tight focusing of a generalized Poincaré beam using a Richards–Wolf formalism. Conventional Poincaré beams are superpositions of two Laguerre–Gaussian beams with orthogonal polarization, while the generalized Poincaré beams …
View article: Transverse Spin Hall Effect and Twisted Polarization Ribbons at the Sharp Focus
Transverse Spin Hall Effect and Twisted Polarization Ribbons at the Sharp Focus Open
In this work, using a Richards-Wolf formalism, we derive explicit analytical relationships to describe vectors of the major and minor axes of polarization ellipses centered in the focal plane when focusing a cylindrical vector beam of inte…
View article: Fourier-invariant autofocused Laguerre-Gaussian beams
Fourier-invariant autofocused Laguerre-Gaussian beams Open
We study a new Laguerre - Gaussian (LG) beam, which differs from conventional LG mode beams that preserve the structure of the intensity distribution up to scale. The proposed beam does not retain its structure upon free-space propagation …
View article: Enhancing the Spin Hall Effect of Cylindrically Polarized Beams
Enhancing the Spin Hall Effect of Cylindrically Polarized Beams Open
Two linked gear wheels in a micromachine can be simultaneously rotated in opposite directions by using a laser beam that has in its section areas the spin angular momentum (SAM) of the opposite sign. However, for instance, a cylindrical ve…
View article: Structurally Invariant Higher-Order Ince-Gaussian Beams and Their Expansions into Hermite-Gaussian or Laguerre-Gaussian Beams
Structurally Invariant Higher-Order Ince-Gaussian Beams and Their Expansions into Hermite-Gaussian or Laguerre-Gaussian Beams Open
Paraxial beam modes, which propagate in space and focus without changing their transverse intensity pattern, are of great value for multiplexing transmitted data in optical communications, both in waveguides and in free space. The best-kno…
View article: Spin angular momentum of Gaussian beams with several polarization singularities
Spin angular momentum of Gaussian beams with several polarization singularities Open
We study a paraxial vector Gaussian beam with several polarization singularities located on a circle. Such a beam is superposition of a cylindrically polarized Laguerre-Gaussian beam and a linearly polarized Gaussian beam. It is found that…
View article: Spin Hall Effect of Two-Index Paraxial Vector Propagation-Invariant Beams
Spin Hall Effect of Two-Index Paraxial Vector Propagation-Invariant Beams Open
We investigate a simple paraxial vector beam, which is a coaxial superposition of two single-ringed Laguerre–Gaussian (LG) beams, linearly polarized along the horizontal axis, with topological charges (TC) n and −n, and of two LG beams, li…
View article: Vector Light Field Immediately behind an Ideal Spherical Lens: Spin–Orbital Conversion, Additional Optical Vortices, Spin Hall Effect, Magnetization
Vector Light Field Immediately behind an Ideal Spherical Lens: Spin–Orbital Conversion, Additional Optical Vortices, Spin Hall Effect, Magnetization Open
The Richards–Wolf formulas not only adequately describe a light field at a tight focus, but also make it possible to describe a light field immediately behind an ideal spherical lens, that is, on a converging spherical wave front. Knowing …
View article: Topological Charge of Propagation-Invariant Laser Beams
Topological Charge of Propagation-Invariant Laser Beams Open
If a vortex propagation-invariant beam is given by all its intensity nulls, then its topological charge (TC) can be defined easily: its TC is equal to the sum of topological charges of all optical vortices in these intensity nulls. If, how…
View article: Spin angular momentum and angular harmonics spectrum of two-order polarization vortices at the tight focus
Spin angular momentum and angular harmonics spectrum of two-order polarization vortices at the tight focus Open
We investigate the spin angular momentum (SAM) of two-order cylindrical vector beams at the tight focus. Such beams are a generalization of the conventional cylindrical vector beams since the transverse field components on the Cartesian ax…
View article: Focusing a vortex beam with circular polarization: angular momentum
Focusing a vortex beam with circular polarization: angular momentum Open
Based on the Richards-Wolf formalism, we obtain two different exact expressions for the angular momentum (AM) density in the focus of a vortex beam with the topological charge n and with right circular polarization. One expression for the …
View article: Magnetic Antiskyrmions in Two-Dimensional van der Waals Magnets Engineered by Layer Stacking
Magnetic Antiskyrmions in Two-Dimensional van der Waals Magnets Engineered by Layer Stacking Open
Magnetic skyrmions and antiskyrmions are topologically protected quasiparticles exhibiting a whirling spin texture in real space. Antiskyrmions offer some advantages over skyrmions as they are expected to have higher stability and can be e…
View article: Spin Hall Effect in Paraxial Vectorial Light Beams with an Infinite Number of Polarization Singularities
Spin Hall Effect in Paraxial Vectorial Light Beams with an Infinite Number of Polarization Singularities Open
Elements of micromachines can be driven by light, including structured light with phase and/or polarization singularities. We investigate here a paraxial vector Gaussian beam with an infinite number of polarization singularities residing e…
View article: Controlling the Spin Hall Effect in the Sharp Focus of an Axial Superposition of Two Optical Vortices with Left- and Right-Handed Circular Polarization
Controlling the Spin Hall Effect in the Sharp Focus of an Axial Superposition of Two Optical Vortices with Left- and Right-Handed Circular Polarization Open
We consider sharp focusing of an axial superposition of two optical vortices with identical topological charges, but different amplitudes and circular polarizations of different signs. The ratio of the amplitudes of the two beams is a para…
View article: Optical Helicity of Light in the Tight Focus
Optical Helicity of Light in the Tight Focus Open
Using the Richards–Wolf formalism, we obtain explicit analytical expressions for the optical helicity density at the tight focus of four different light beams: a linearly polarized optical vortex, an optical vortex with right-handed circul…
View article: Generalized Asymmetric Hermite–Gaussian and Laguerre–Gaussian Beams
Generalized Asymmetric Hermite–Gaussian and Laguerre–Gaussian Beams Open
We derive analytical formulae for the complex amplitudes of variants of generalized Hermite–Gaussian (HG) and Laguerre–Gaussian (LG) beams. We reveal that, at particular values of parameters of the exact solution of the paraxial propagatio…
View article: Double and Square Bessel–Gaussian Beams
Double and Square Bessel–Gaussian Beams Open
We obtain a transform that relates the standard Bessel–Gaussian (BG) beams with BG beams described by the Bessel function of a half-integer order and quadratic radial dependence in the argument. We also study square vortex BG beams, descri…
View article: Hall Effect at the Focus of an Optical Vortex with Linear Polarization
Hall Effect at the Focus of an Optical Vortex with Linear Polarization Open
The tight focusing of an optical vortex with an integer topological charge (TC) and linear polarization was considered. We showed that the longitudinal components of the spin angular momentum (SAM) (it was equal to zero) and orbital angula…
View article: Spin Hall Effect in the Paraxial Light Beams with Multiple Polarization Singularities
Spin Hall Effect in the Paraxial Light Beams with Multiple Polarization Singularities Open
Elements of micromachines can be driven by light, including structured light with phase and/or polarization singularities. We investigate a paraxial vectorial Gaussian beam with multiple polarization singularities residing on a circle. Suc…
View article: Spin Hall Effect of Double-Index Cylindrical Vector Beams in a Tight Focus
Spin Hall Effect of Double-Index Cylindrical Vector Beams in a Tight Focus Open
We investigate the spin angular momentum (SAM) of double-index cylindrical vector beams in tight focus. Such a set of beams is a generalization of the conventional cylindrical vector beams since the polarization order is different for the …
View article: Generalized Poincaré Beams in Tight Focus
Generalized Poincaré Beams in Tight Focus Open
We study the tight focus of generalized (hybrid) Poincaré beams. A conventional Poincaré beam is a coaxial superposition of two optical vortices, one with left circular polarization and a topological charge (TC) of m, while the other has a…
View article: Angular and Orbital Angular Momenta in the Tight Focus of a Circularly Polarized Optical Vortex
Angular and Orbital Angular Momenta in the Tight Focus of a Circularly Polarized Optical Vortex Open
Based on the Richards-Wolf (RW) formalism, we obtain two different exact expressions for the angular momentum (AM) density of light in the focus of an optical vortex with a topological charge n and right circular polarization. One expressi…