arXiv subjects

Maxim Gorkunov

Publications and source records attributed to Maxim Gorkunov.

6 recordsLinked to original sources

arXiv2026

Optical Control of Chirality by Ultrafast Symmetry Breaking in Membrane Metasurfaces

Chirality underpins a wide range of light-matter interactions, yet methods for its dynamic control in photonic systems remain limited. Here, we demonstrate ultrafast all-optical control of chirality in silicon metasurfaces through transient symmetry breaking. Our approach exploits photonic eigenstates of opposite spatial parity engineered to be highly susceptible to symmetry perturbations. Optical excitation generates free carriers that establish a transient refractive-index gradient across the membrane thickness, breaking out-of-plane mirror symmetry and facilitating hybridization of the parity-opposite modes into chiral photonic states. This enables the reversible creation and modulation of chirality on a 10-100 ps timescale, manifested by pronounced changes in the metasurface circular dichroism. By dynamically reconfiguring a fundamental symmetry property of the photonic structure rather than merely its optical response, our work establishes a route towards ultrafast control of chiral light-matter interactions and opens opportunities for active nanophotonic and information processing technologies.

physics.optics↗

arXiv2025

Maximal optical chirality via mode coupling in bilayer metasurfaces

Recent advances in the physics of resonant optical metasurfaces allowed to realize the so-called maximum chirality of planar structures by engineering their geometric parameters. Here we employ bilayer membrane metasurfaces with a square lattice of rotated C$_4$-symmetric holes and uncover very different scenarios of chirality maximization by virtue of strong coupling of photonic eigenmodes of the membranes supplemented by smart engineering of dissipation losses. Our findings substantially expand the class of planar maximally chiral resonant surfaces feasible for widespread nanolithography techniques desired for metaphotonic applications in chiral sensing, chiral light emission, detection and polarization conversion.

physics.optics↗

arXiv2024

Chiral Dichroism in Resonant Metasurfaces with Monoclinic Lattices

We demonstrate that chiral response can be achieved in resonant metasurfaces with a monoclinic lattice symmetry (the so-called Bravais oblique lattices) where the mirror symmetry is broken by the lattice asymmetry and also by a substrate, whereas each individual meta-atom remains fully achiral. We describe the underlying physics by introducing a mode chirality parameter as a quantitative measure of the lattice chiral eigenmodes. We confirm experimentally selective linear and nonlinear chiral interaction of resonant silicon metasurfaces with circularly polarized light.

physics.optics↗

arXiv2010

Metamaterial tuning by manipulation of near-field interaction

We analyze the near-field interaction between the resonant sub-wavelength elements of a metamaterial, and present a method to calculate the electric and magnetic interaction coefficients. We show that by adjusting the relative configuration of the neighboring split ring resonators it becomes possible to manipulate this near-field interaction, and thus tune the response of metamaterials. We use the results of this analysis to explain the experimentally observed tuning of microwave metamaterials.

physics.optics↗

arXiv2009

Structural tunability in metamaterials

We propose a novel approach for efficient tuning of the transmission characteristics of metamaterials through a continuous adjustment of the lattice structure, and confirm it experimentally in the microwave range. The concept is rather general and applicable to various metamaterials as long as the effective medium description is valid. The demonstrated continuous tuning of metamaterial response is highly desirable for a number of emerging applications of metamaterials including sensors, filters, switches, realizable in a wide frequency range.

physics.optics↗

arXiv2005

Effect of microscopic disorder on magnetic properties of metamaterials

We analyze the effect of microscopic disorder on the macroscopic properties of composite metamaterials and study how weak statistically independent fluctuations of the parameters of structure elements can modify their collective magnetic response and left-handed properties. We demonstrate that even a weak microscopic disorder may lead to a substantial modification of the metamaterial magnetic properties, and 10% deviation in the parameters of the microscopic resonant elements may lead to a substantial suppression of wave propagation in a wide frequency range. A noticeable suppression occurs also if more than 10% of resonant magnetic elements possess strongly different properties, but in this latter case the defects can create an additional weak resonant line. These results are of the key importance for characterizing and optimizing the novel composite metamaterials with left-handed properties at terahertz and optical frequencies.

cond-mat.dis-nn↗