A5084954957- Liquid Crystal Research Advancements
- Photonic Crystals and Applications
- Orbital Angular Momentum in Optics
- Surfactants and Colloidal Systems
- Plant Reproductive Biology
- Mechanical and Optical Resonators
- Gold and Silver Nanoparticles Synthesis and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Molecular spectroscopy and chirality
- Pickering emulsions and particle stabilization
- Experimental and Theoretical Physics Studies
- Engineering Education and Pedagogy
- Nonlinear Optical Materials Studies
- Force Microscopy Techniques and Applications
- Micro and Nano Robotics
- Plant and animal studies
- Advanced biosensing and bioanalysis techniques
- Microfluidic and Bio-sensing Technologies
- Photorefractive and Nonlinear Optics
- Biocrusts and Microbial Ecology
- Silk-based biomaterials and applications
- Diffusion and Search Dynamics
- Plasmonic and Surface Plasmon Research
- Iron oxide chemistry and applications
- Optical Polarization and Ellipsometry
Centre National de la Recherche Scientifique
2012-2025
Université de Bordeaux
2018-2025
Laboratoire Ondes et Matière d'Aquitaine
2018-2022
University of Chicago
2015-2018
Laboratoire Charles Coulomb
2014-2017
Université de Montpellier
2017
Institut des NanoSciences de Paris
2012-2016
Sorbonne Université
2010-2016
Université Paris Cité
2015
Besides nanostructured materials, individual particles are key elements for nanosciences. The structuring properties of liquid crystals (LCs) appealing to assemble them, organize them on substrates or design functional composites. We present here an overview particles/LC systems, the size dispersed being larger than typical LC length. first summarize large number advances made these last 10 years concerning microparticles assemblies. then discuss evolution relevant interactions between...
In the presence of oriented smectic liquid crystal defects, hybrid systems nanoparticles/liquid crystals form straight chains nanoparticles length longer than tens micrometers and width equal to one single nanoparticle. The interparticle distance in a chain can be varied between few 1.5 nm, highlighting control optical absorption by light polarization monitored gold nanoparticle concentration.
We show that the study of gold nanoparticle self-assemblies induced by a liquid crystal matrix reveals intimate distorted structure existing prior to nanoparticles' incorporation. also how this controls spacing between nanoparticles in self-assemblies. have created hybrid films cholesteric (CLC) and nanoparticles, CLC being deformed competing anchorings at its two interfaces. Whereas previous results evidenced formation only slightly anisotropic clusters for large (diameter 20 nm), we now...
Combining optical microscopy, synchrotron X-ray diffraction and ellipsometry, we studied the internal structure of linear defect domains (oily streaks) in films a smectic liquid crystal 8CB with thicknesses range 100–300 nm. These are confined between air rubbed PVA polymer substrate which imposes hybrid anchoring conditions (normal unidirectional planar, respectively). We show how presence or absence dislocations controls highly deformed thin films. Each domain contains layers curved shape...
Arrays of liquid crystal defects—linear smectic dislocations—are used to trap semiconductor CdSe/CdS dot‐in‐rods which behave as single‐photon emitters. Measurements the emission diagram are combined together with measurements emitted polarization single It is shown that confined parallel linear defects allow for a minimization disorder energy associated dislocation cores. demonstrated electric dipoles dot‐in‐rods, tilted respect rods, remain oriented in plane including and perpendicular...
We report on the design, fabrication and performance of novel flat-optical spin-orbit modal beam shapers made from silica glass by femtosecond laser nanostructuring technology, choosing Laguerre-Gauss basis as a case study. The basic design principle involves endowing transparent dielectric material, initially isotropic homogeneous, with doubly inhomogeneous anisotropic characteristics (optical axis orientation birefringence). quantitative structural characterization fabricated devices is...
We investigated composite films of gold nanoparticles (NPs)/liquid crystal (LC) defects as a model system to understand the key parameters, which allow for an accurate control NP anisotropic self-assemblies using soft templates. combined spectrophotometry, Raman spectroscopy, and grazing incidence small-angle X-ray scattering with calculations dipole coupling models sphere interactions. demonstrate that dense arrays elementary edge dislocations can strongly localize small NPs along defect...
In this Letter, we show how advanced hierarchical structures of topological defects in the so-called smectic oily streaks can be used to sequentially transfer their geometrical features gold nanospheres. We use two kinds defects, 1D dislocations and 2D ribbon-like defects. The large trapping efficiency dislocation cores not only surpasses that elastically distorted zones around but also one defect. This enables formation a number aligned NP chains within quasi-fully filled without any...
Studies of nanoparticle-based optical matter have only considered spherical constituents. Yet nanoparticles with other shapes are expected to different local electromagnetic field distributions and therefore interactions neighbors in arrays. Therefore, one would expect their dynamics be as well. We investigate directed-assembly ordered arrays plasmonic nanoplatelets line traps demonstrating reconfigurability the array by altering phase gradient via holographic beam shaping. The weaker forces...
Local full Mueller matrix measurements in the Fourier plane of a microscope lens were used to determine internal anisotropic ordering periodic linear arrays smectic liquid crystal defects, known as 'oily streaks'. We propose single microstructure-dependent model taking into account dielectric function that reproduces layers orientation and organization oily streaks. The calculated elements are compared measured data reveal anchoring mechanism streaks on substrate evidence presence new type...
Abstract Modality is a generic concept of wave-optics at the basis optical information and communications. One challenges photonics technologies based on orbital angular momentum consists in production modal content for both azimuthal radial degrees freedom. This basically requires shaping complex amplitude an incident light beam, which usually made up from adaptive spatial modulators or bespoke devices. Here, we report experimental attempt recent theoretical proposal [ Opt. Lett. 42 , 1966...
Using nCB films adsorbed on MoS 2 substrates studied by x-ray diffraction, optical microscopy and Scanning Tunneling Microscopy, we demonstrate that ordered interfaces with well-defined orientations of dipoles induce planar anchoring locked along the or alkyl chains, which play role easy axes. For two alternating bi-stability can be obtained. The results are explained using introduction fourth order terms in phenomenological potential, leading to demonstration first transition these systems....
Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they display very strong Kerr Cotton-Mouton effects (i.e., field-induced particle orientation). For many examples these colloidal suspensions, the solvent is water, which hinders most electro-optic applications. Here, for...
Abstract Optical information and communication technologies are essentially based on the ability to shape light field, either at transmission or reception of optical signal. Nowadays, wavelength polarization state already implemented in current telecom architectures adding spatial structuring field as a novel degree freedom enhance data rate is desirable. In this context, development devices modes belonging orthogonal basis remains challenging. Here, context singular optics, work reports...
STM measurements on HOPG, MoS<sub>2</sub>, and Au[111] together with DFT calculations were employed for establishing of the origin self-assembly 4-cyano-4′-<italic>n</italic>-decylbiphenyl (10CB) kinked row structures.
We experimentally report on nonvolatile and rewritable binary optical memory where the photon spin state controls polarity of optically recorded localized orientational distortions in liquid crystals, which behave as elastic quasiparticles having long-term storage capabilities. The effect is made possible by chiral nature crystal mesophase, while supramolecular 'spinbits' results from light-matter interaction involving spin-angular momentum transfer light to matter.