arXiv subjects

Natalia Litchinitser

Publications and source records attributed to Natalia Litchinitser.

3 recordsLinked to original sources

arXiv2026

Two-color solitons in Kerr third harmonic generation model

We investigate two-color, two dimensional spatially localized light modes in a resonant Kerr third-harmonic generation model. Using computational tools, we identify two distinct families of localized states. Unlike the single-component 2D nonlinear Schrödinger equation and previously studied non-resonant two-color systems, the dynamics are not dictated by a universal critical power, but depend on the distribution of power between the harmonics. The "fundamental-dominated" family acts as a "dynamical separatrix" between simultaneous collapse and joint diffraction, whereas the "third-harmonic-dominated" family does not. We further identify resonant collapse events accompanied by strong oscillations of the third harmonic, revealing a collapse mechanism absent from standard Kerr self-focusing.

physics.optics↗

arXiv2025

Deep Learning Driven Enhancement of Optical Vortex Line Robustness in Atmospheric Turbulence

The stability of optical vortex structures in turbulent environments is critical for their applications in optical communication, quantum information, and structured light technologies. Although topological invariants, such as crossings and linking numbers, are fundamentally invariant, recent studies reveal that their observed values deteriorate considerably in turbulent conditions due to environmental effects. In this study, we introduce an alternative approach based on the geometric stability of three-dimensional singularity line shapes, demonstrating that shape-based tracing of singularities outperforms both topological and spectral methods in turbulence. To test this concept, we propose Flower Beams, a novel class of structured optical fields featuring controllable petal-like singularity morphologies. We construct an 81-element optical alphabet and classify these structures after turbulence using deep learning. Our findings reveal that shape-based tracing achieves classification accuracy exceeding 90% in the weaker turbulence regimes and remains highly competitive even in stronger turbulence, significantly outperforming spectral and topology-based approaches. Experimental results confirm that the predicted shape stability holds in real-world conditions. This study stablishes the shape of the singularities' lines as a scalable and resilient alternative for structured light tracing and transmission, opening new avenues for turbulence-robust-applications.

physics.optics↗

arXiv2014

Metamaterial all-optical switching based on resonance mode coupling in dielectric meta-atoms

All-optical switching based on optical nonlinearity must undergo complex processes of light-mater interaction in atom and electron scale, so a relative high power and long response time is required, that construct main bottlenecks in all-optical technology. In this paper, we propose a new mechanism for building all-optical switching based on a change resonance modes of meta-atoms in metamaterials, not involved optical nonlinearity of materials. A metamaterial composed of cubic dielectric meta-atoms periodically embedded in a background matrix is designed and constructed. All-optical switch functionality by modulating the resonance modes in meta-atoms utilizing a vertical direction switch light whose power is the same value with that of the signal light is demonstrated in microwave range theoretically and experimentally. This results represent a significant step towards obtaining all-optical switching devices with extremely low threshold power and high switching speed.

cond-mat.mtrl-sci↗