Searcharxiv⌕ Search

arXiv · 2610.35672

Theoretical description of high-harmonic spectroscopy for uniaxial nematic and isotropic liquid crystals

Abstract

Enabled by their controllable optical anisotropy, liquid crystals form a cornerstone of linear optical and display technologies. Bringing the versatile platform into the nonlinear regime, we explore its nonlinear optical anisotropy by high-order harmonic generation spectroscopy. Through a comprehensive study targeting gas, liquid, nematic, and crystalline phases, we present a semi-empirical tight-binding approach that provides insight into the intermolecular character of ultrafast light-driven electron dynamics across soft-matter mesophases. We demonstrate how intermolecular electron hybridization enables spectroscopic access to structural properties, such as the nematic director and order parameter. Outlining such foundational mechanisms opens avenues towards nonlinear liquid crystal devices and ultrafast soft-matter spectroscopies.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Simon Vendelbo Bylling Jensen, Marta L. Murillo-Sánchez, Andrea Annunziata, Angel Rubio, Laura Cattaneo, Nicolas Tancogne-Dejean. 2026-10-26. Theoretical description of high-harmonic spectroscopy for uniaxial nematic and isotropic liquid crystals. https://arxiv.org/abs/2610.35672

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Interaction-Induced Topological Transport of Extended Doublons

Topological boundary states are a defining feature of topological systems, providing robust transport protected against perturbations. While such states are commonly engineered in non-interacting systems, how to realize interaction-induced topological states composed of only few particles has remained experimentally unexplored thus far. In this work, we realize such states using a driven photonic lattice as a linear analogue platform. We observe the formation of spatially extended bound states of two interacting particles, in which the particles remain correlated while occupying different lattice sites. At discrete values of the local interaction, these bound states support robust transport governed by a topological phase arising from drive-induced correlated hopping. Our results establish an experimentally accessible route to interaction-driven topology beyond single-particle physics and provide a versatile framework for exploring correlated few-particle phenomena across different physical platforms.

physics.optics↗

Recovering topological information of light by topological learning

The evolution of modern-day communication networks towards enhanced capacity and robustness is driving interest in topological light wave as a next-generation information carrier. However, harnessing its potential is hindered by the lack of an effective topological reader, particularly when strong disorder renders conventional readout intractable. Here we address this by introducing TOPO$^{2}$, an artificial intelligence framework that leverages on topological learning to recover topological information from light. We demonstrate it on highly distorted optical fields with embedded Skyrmion topologies, showing that we can extract the topological numbers in a single shot with just a conventional camera. We showcase its capability in a TOPO$^{2}$-based communication scheme, sending and recovering information encoded in a topological alphabet, confirming that it outperforms conventional approaches. Our connection of topological photonics with topological AI as a powerful paradigm for robust high-capacity information encoding and processing opens a new path towards topological information optics.

physics.optics↗

Video-rate quantitative phase and polarimetric imaging (QP2I) for label-free imaging of contracting muscle cells

Quantitative phase imaging (QPI) has become a standard approach for label-free microscopy of transparent specimens, mapping the optical path length. However, the isotropic phase is blind to the molecular order underlying optical anisotropy. Implementations that also add quantitative contrast to birefringence rely on multi-frame illumination or polarization-state scanning, or on dedicated interferometric hardware and thus trade away acquisition speed or the simplicity of a standard microscope. We present Quantitative Phase and Polarimetric Imaging (QPPI), a computational imaging framework that converts a standard differential interference contrast (DIC) microscope with a polarization camera into a single-shot, video-rate, dual-contrast imaging system. We developed a new globally regularized phase reconstruction that eliminates artifacts of prior DIC-to-QPI approaches, providing quantitative phase information, and used per-pixel Stokes-based reconstruction to obtain quantitative anisotropic retardance. We validate the approach across simulations, static reference targets, fixed muscle tissue and living dynamically moving cells. QPPI enables all-optical and label-free studies of contractile dynamics in live cardiomyocytes. It provides both structural and functional readouts at sufficient frame rates to resolve fast cardiomyocyte contractions. Conventional fluorescent labels bleach over time, perturb physiology, and preclude long-term monitoring. Instead, QPPI enables long-term, label-free interrogation of dynamic cellular processes at quantitative contrast and provides structural readouts similar to those provided by established fluorescent labels, such as frame-by-frame sarcomere length. It also offers previously inaccessible measurements, like quantitative analysis of retardance changes during muscle contraction, which provides a direct optical signature of muscle photoelasticity.

physics.optics↗