arXiv subjects

Andrey Pryamikov

Publications and source records attributed to Andrey Pryamikov.

5 recordsLinked to original sources

arXiv2026

Reverse Energy Flows in Two-Dimensional Photonic Crystals and Analogies with Vortex Formation and Analogous Flows in Hydrodynamics

This paper examines the connection between photonic band-gap formation in two types of two-dimensional photonic crystals and the emergence of reverse electromagnetic energy flows generated by linearly polarized plane waves incident on a photonic-crystal slab. We show that these reverse energy flows, observed in both transmitted and reflected fields, originate from vortex structures in the Poynting vector. The resulting energy-flow patterns exhibit striking analogies to vortex formation in fluid motion past obstacles. The geometry and dynamics of the Poynting-vector vortices determine whether the incident electromagnetic energy is impeded, leading to the formation of photonic band gaps, or instead guided through the structure, enabling transmission.

physics.optics↗

arXiv2025

Reverse energy flows: the physical mechanism underling dramatic reduction of loss in hollow-core fibers

Hollow-core fibers (HCFs) with claddings composed of silica glass capillaries have recently attracted a great deal of attention following the demonstration of optical loss levels lower than those of conventional telecommunication fibers. It is well established already that optical losses in HCFs are highly sensitive to both the wavelength and the geometry of the cladding capillaries. The underlying physical mechanisms behind reducing loss with the change of HCF design parameters while keeping the same fiber structure are not yet fully understood. In this work, we investigate the relationship between light localization and corresponding decrease of losses in HCFs and the distribution of reverse energy fluxes in air-core modes. We show here that the shape of the capillaries plays a crucial role in controlling radial energy backflows that influence light confinement and the energy leakage from air-core modes of HCFs. Through numerical modeling, we demonstrate that optimizing the capillary geometry to tailor the distribution of reverse radial energy fluxes leads to a substantial reduction in transmission losses even in fibers with relatively simple cladding structures. Consideration of the energy flows and observed occurrences of vortex of the Poynting vector allows us to a draw an interesting interdisciplinary analogy with the hydrodynamical system with suppressed backward flow - Tesla valve. We believe that combination of singular optics and energy fluxes analysis provides valuable physical insight into the mechanisms governing waveguiding in HCFs offering a pathway toward novel designs with minimized leakage loss.

physics.optics↗

arXiv2021

Phase dislocations in hollow core waveguides

This paper discusses the basic concepts of phase dislocations and vortex formation in the electric fields of fundamental air core mode of hollow core waveguides with specific types of rotational symmetry of the core cladding boundary. Analysis of the behavior of the electric field phase in the transmission bands shows that the mechanism of light localization in the hollow core waveguides with discrete rotational symmetry of the core cladding boundary cannot be completely described by the ARROW model. For an accurate description of the phase behavior, it is necessary to account for phase jumps of the magnitude of pi when passing through the phase dislocations.

physics.optics↗

arXiv2019

Light transport and vortex-supported wave-guiding in micro-structured optical fibres

In hydrodynamics, vortex generation upon the transition from smooth laminar flows to turbulence is generally accompanied by increased dissipation. However, plane vortices can provide transport barriers and decrease losses, as it happens in numerous geophysical, astrophysical flows and in tokamaks. Photon interactions with matter can affectlight transportin waveguides in unexpected and somewhat counterintuitive ways resembling fluid dynamics. Here, we demonstrate dramatic impact of light vortex formation in micro-structured optical fibres on the energy dissipation. We show possibility of vortices formationin both solid core and hollow core fibres on the zero amplitude lines in the cladding. We find that vortices reduce light leakage by three orders of magnitude, effectively improving wave guiding. A strong light localization based on the same principle can also be achieved in the negative curvature hollow core fibres.

physics.optics↗

arXiv2010

Surface Bloch waves mediated heat transfer between two photonic crystals

We theoretically investigate the non-radiative heat transfer between two photonic crystals separated by a small gap in non-equilibrium thermal situation. We predict that the surface Bloch states coupling supported by these media can make heat exchanges larger than those measured at the same separation distance between two massive homogeneous materials made with the elementary components of photonic crystals. These results could find broad applications in near-field technologies.

physics.optics↗