arXiv subjects

Anton Sdobnov

Publications and source records attributed to Anton Sdobnov.

4 recordsLinked to original sources

arXiv2026

Chiral phase memory of twisted light through multiple scattering

Chiroptical signals, optical responses sensitive to molecular handedness, are rapidly suppressed by multiple scattering, fundamentally limiting their use in turbid media. Here we show that coupling molecular chirality to the topological structure of twisted light generates a protected phase observable that survives strong scattering. When Laguerre-Gaussian beams carrying orbital angular momentum propagate through chiral media, spin-orbit interaction converts circular birefringence into an azimuthal rotation of the helical wavefront. Remarkably, this chiral phase memory persists at scattering strengths that fully depolarize conventional beams, with the rotation magnitude preserved quantitatively between transparent solutions and strongly scattering tissue. The sign of the azimuthal rotation encodes molecular handedness: opposite enantiomers produce mirror-symmetric phase maps even after multiple scattering. Differential measurements between conjugate topological charges isolate the chiral contribution while cancelling achiral background, enabling the resolution of refractive-index changes of order 10-6. These results establish topological phase observables as robust carriers of weak chiral light-matter interactions in complex media, opening new routes for chiroptical spectroscopy and sensing beyond the ballistic-photon regime.

physics.optics↗

arXiv2025

Decoding Orbital Angular Momentum in Turbid Tissue-like Scattering Medium via Fourier-Domain Deep Learning

Structured light beams carrying orbital angular momentum (OAM), such as Laguerre-Gaussian modes, are promising tools for high-capacity optical communications and advanced biomedical imaging. However, multiple scattering in turbid media distorts their phase and amplitude, complicating the retrieval of topological charge. We introduce VortexNet, a deep learning architecture that integrates an Angular Fourier Transform to explicitly extract rotational symmetries of OAM beams from experimentally acquired intensity and interference patterns. By transforming spatial information into the angular frequency domain, VortexNet isolates azimuthal features that persist despite scattering, enabling accurate topological charge classification even in complex optical environments. The results reveal that OAM-specific angular correlations can survive multiple scattering and be decoded through angular-domain learning. This establishes a new paradigm for structured-light analysis in complex medium, where deep learning enables the recovery of topological information beyond the reach of classical optics, paving the way for resilient photonic systems in communication, sensing, and imaging.

physics.optics↗

arXiv2024

Insights into Polycrystalline Microstructure of Blood Films with 3D Mueller Matrix Imaging Approach

We introduce a 3D Mueller Matrix (MM) image reconstruction technique using digital holographic approach for the layer-by-layer profiling thin films with polycrystalline structures, like dehydrated blood smears. The proposed method effectively extracts optical anisotropy parameters for a detailed quantitative analysis. The investigation revealed the method sensitivity to subtle changes in optical anisotropy properties resulting from alterations in the quaternary and tertiary structures of blood proteins, leading to disturbances in crystallization structures at the macro level at the very early stage of a disease. Spatial distributions of linear and circular birefringence and dichroism are analyzed in partially depolarizing polycrystalline blood films obtained from healthy tissues and cancerous prostate tissues at various stages of adenocarcinoma. Changes in the values of the 1st to 4th order statistical moments, characterizing the distributions of optical anisotropy in different phase sections of the smear volumes, are observed and quantified. Comparative analysis of optical anisotropy distributions from healthy patients highlighted the 3rd and 4th order statistical moments for linear and circular birefringence and dichroism as the most promising for diagnostic purposes. We achieved an excellent accuracy (>90%) for early cancer diagnosis and differentiation of its stages, demonstrating the techniques significant potential for rapid and accurate definitive cancer diagnosis compared to existing screening approaches.

physics.med-ph↗

arXiv2023

Phase Memory of Orbital Angular Momentum in Multiple Scattering Environment

Recent advancements in wavefront shaping techniques have facilitated the study of complex structured light's propagation with orbital angular momentum (OAM) within various media. The introduction of a spiral phase modulation to the Laguerre-Gaussian (LG) beam during its paraxial propagation is facilitated by the negative gradient of the medium's refractive index's temporal change, resulting in an accelerated retardation in OAM twist. This approach attains remarkable sensitivity to even the slightest variations in the medium's refractive index (10^(-6)). The phase memory of OAM is revealed as the ability of twisted light preserving initial helical phase even propagating through the turbid tissue-like multiple scattering medium. The results confirm fascinating opportunities of the exploiting OAM light in biomedical applications, e.g. such as non-invasive trans-cutaneous glucose diagnosis and optical communication through biological tissues and other optically dense media.

physics.optics↗