arXiv subjects

S. A. Dyakov

Publications and source records attributed to S. A. Dyakov.

10 recordsLinked to original sources

arXiv2026

A complete photoluminescence polarization palette from a photonic-crystal slab

Integrated light sources with tailored polarization are essential for integrated photonics, optical communication, sensing, and structured-light applications. However, generating a broad set of polarization states from spontaneous emission usually relies on structures with broken mirror, rotational, or inversion symmetries, or on emitters with predefined polarization properties. Here, we demonstrate a complete photoluminescence polarization palette in a single achiral photonic-crystal slab with a hexagonal lattice of holes and embedded self-assembled Ge(Si) nanoislands. We show that the polarization of the emitted light is governed by the interplay among modes with different symmetries rather than by the properties of unpolarized emitters. Along the high-symmetry directions of the Brillouin zone, symmetry enforces purely linear emission and enables direct polarization-based classification of the photonic-crystal modes. Away from these directions, all Stokes parameters become non-zero, providing full-Stokes control of photoluminescence and highly polarized emission. We further demonstrate polarization vortices associated with symmetry-protected and Friedrich-Wintgen bound states in the continuum, as well as radiating polarization singularities not associated with bound states in the continuum. Through appropriate geometric optimization, the same platform supports photoluminescence with a full polarization palette as well as polarization vortices. Our results establish achiral photonic-crystal slabs as monolithic sources of symmetry-programmable photoluminescence polarization.

physics.optics↗

arXiv2025

Quadrupole Mie-resonant metamaterial

Dense lattices of photonic crystals can serve as artificial materials, with light propagation in these structures described by effective material parameters that surpass the capabilities of natural materials. In this study, we introduce a metamaterial that supports quadrupole magnetization, a characteristic rarely observed in existing structures. We experimentally demonstrate a magnetic quadrupole metamaterial associated with Mie-resonance-excited stop bands below the Bragg band. Additionally, we develop a theoretical model that addresses both dispersion and boundary conditions within this framework. Using a Fabry-Perot resonator as a case study, we validate our model and reveal that the quadrupole metamaterial can exhibit a markedly different reflection/transmission spectrum, including zero reflection at normal incidence. Our findings underscore the practical potential for both experimental and theoretical investigations of metamaterials that extend beyond the dipole approximation.

physics.optics↗

arXiv2020

Dimensional confinement and waveguide effect of Dyakonov surface waves in twisted confined media

We theoretically study Dyakonov surface waveguide modes that propagate along the planar strip interfacial waveguide between two uniaxial dielectrics. We demonstrate that due to the one-dimensional electromagnetic confinement, Dyakonov surface waveguide modes can propagate in the directions that are forbidden for the classical Dyakonov surface waves at the infinite interface. We show that this situation is similar to a waveguide effect and formulate the resonance conditions at which Dyakonov surface waveguide modes exist. We demonstrate that the propagation of such modes without losses is possible. We also consider a case of two-dimensional confinement, where the interface between two anisotropic dielectrics is bounded in both orthogonal directions. We show that such a structure supports Dyakonov surface cavity modes. Analytical results are confirmed by comparing with full-wave solutions of Maxwell's equations. We believe that our work paves the way towards new insights in the field of surface waves in anisotropic media.

physics.optics↗

arXiv2020

Thickness-independent narrow resonance in a stack of two plasmonic lattices

Plasmonic lattices consisting of nanoparticles in a homogeneous environment are well known fortheir support of so-called lattice plasmon resonances. They are associated with localized surfaceplasmons coupled to each other via free propagating photons along the structure. In this paper, weexplore modes in a stack of two identical plasmonic lattices. We demonstrate that such a structureis able to support a mode that is positioned strictly on a Rayleigh anomaly and does not shift withthe variation of distance between two lattices in wide limits. Given the fact that period is the moststably reproduced quantity in an experiment, such behavior can be used to simplify the fabricationof structures with resonances at desired energies.

physics.optics↗

arXiv2020

Vertical routing of spinning dipoles radiation from a chiral metamembrane

We propose a perfect photonic router based on a specially designed chiral bi-metasurface membrane for spin-polarized point light sources. Due to the mirror symmetry breaking in the chiral metamembrane, the radiation power flux of the clockwise and counterclockwise spinning dipoles to the opposite sides of the slab becomes different. We show that spinning dipoles in the specially designed chiral D$_4$-symmetrical bi-metasurface membrane can emit light either upwards or downwards depending on their rotation direction. We attribute this phenomenon to the Fano-resonance effect which is a result of the guided modes coupling with the far field. We show the advantage of D$_4$-symmetrical structures for the achievement of 100\% routing efficiency. This phenomenon can find applications in spintronics for spin-selective inter-chip coupling or as a measurement tool of spin polarization in memory cells.

physics.optics↗

arXiv2020

Nanoparticle lattices with bases: Fourier modal method and dipole approximation

The utilization of periodic structures such as photonic crystals and metasurfaces is common for light manipulation at nanoscales. One of the most widely used computational approaches to consider them and design effective optical devices is the Fourier modal method (FMM) based on Fourier decomposition of electromagnetic fields. Nevertheless, calculating of periodic structures with small inclusions is often a difficult task, since they induce lots of high-$k_\parallel$ harmonics that should be taken into account. In this paper, we consider small particle lattices with bases and construct their scattering matrices via discrete dipole approximation (DDA). Afterwards, these matrices are implemented in FMM for consideration of complicated layered structures. We show the performance of the proposed hybrid approach by its application to a lattice, which routes left and right circularly polarized incident light to guided modes propagating in opposite directions. We also demonstrate its precision by spectra comparison with finite element method (FEM) calculations. The high speed and precision of this approach enable the calculation of angle-dependent spectra with very high resolution in a reasonable time, which allows resolving narrow lines unobservable by other methods.

physics.optics↗

arXiv2019

Wide band enhancement of the transverse magneto-optical Kerr effect in magnetite-based plasmonic crystals

The transverse magneto-optical Kerr effect (TMOKE) in magnetite-based magneto-plasmonic crystals is studied experimentally and theoretically. We analyze angle-resolved TMOKE spectra from two types of structures where noble metallic stripes are incorporated inside a thin magnetite film or located on top of a homogeneous film. A multiple wide band enhancement of the TMOKE signal in transmission is demonstrated. The complex dielectric permittivity and gyration are experimentally determined using the ellipsometry technique as well as Faraday rotation and ellipticity measurements. The obtained parameters are used in rigorous coupled wave analysis (RCWA) calculations for studying the optical resonances. Our RCWA calculations of transmittance and TMOKE are in good agreement with the experimental data. The role of guiding and plasmonic modes in the TMOKE enhancement is revealed. We demonstrate that the TMOKE provides rich information about the studied optical resonances.

physics.optics↗

arXiv2018

Magnetic field-free circularly polarized thermal emission from chiral metasurface

Thermal radiation from bulk disorderly placed nonresonant emitters is incoherent, broadband and isotropic. In an external magnetic field the thermal radiation from any source is circularly polarized. Here we propose a thermal radiation source which emits circularly polarized radiation and which is not placed in a magnetic field. The thermal source consists of a slab waveguide with etched chiral metasurface. Due to the absence of a mirror symmetry of the metasurface, the thermally generated electromagnetic waves become circularly polarized. In this letter we discuss the origin of this phenomenon in details. Using the Fourier modal method we analyze the eigenmodes of the structure and the emissivity spectra. We demonstrate that the degree of circular polarization in an optimized structure can be as high as 0.87.

physics.optics↗

arXiv2017

Plasmon-polariton induced modification of silicon nanocrystals photoluminescence in presence of gold nanostripes

We report the results of theoretical and experimental studies of photoluminescence of silicon nanocrystals in the proximity of plasmonic modes of different types. In our samples, the type of plasmonic mode is determined by the filling ratio of a one-dimensional gold grating which covers the thin film with silicon nanocrystals on a quartz substrate. We analyze the extinction and photoluminesce spectra of silicon nanocrystals and show that the emitted light is coupled to the corresponding plasmonic mode. We also demonstrate the modification of the extinction and photoluminesce spectra under the transition from surface plasmon-polaritons to waveguide plasmon-polaritons with the decrease of the gold filling ratio from 1 to 0.35. Finally, we analyze the contribution of individual silicon nanocrystals to the overall photoluminescence intensity. We conclude that silicon nanocrystals ensemble can be broken down into optically bright and optically dark nanocrystals. The experimental extinction and photoluminescence spectra are in good agreement with theoretical calculations performed by the Fourier modal method in the scattering matrix form.

physics.optics↗

arXiv2014

Near field thermal memory device

We report the concept of a near-field memory device based on the radiative bistability effect in the system of two closely separated parallel plates of SiO$_2$ and VO$_2$ which exchange heat by thermal radiation in vacuum. We demonstrate that the VO$_2$ plate, having metal-insulator transition at 340 K, has two thermodynamical steady-states. One can switch between the states using an external laser impulse. We show that due to near-field photon tunneling between the plates, the switching time is found to be only 5 ms which is several orders lower than in case of far field.

cond-mat.mtrl-sci↗