Timothée Toury - Academia.edu (original) (raw)

Papers by Timothée Toury

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

The first off-resonance hyperpolarizabilities ( (0)) of bisubstituted carotenoids are computed an... more The first off-resonance hyperpolarizabilities ( (0)) of bisubstituted carotenoids are computed and analyzed using a quasiparticle, collective electronic oscillators (CEO) representation. The few oscillators which dominate the response are identified by solving the time dependent Hartree-Fock equations for the reduced single electron density matrix. The variations of these oscillators and the relevant anharmonicities with bridge length are studied. The present approach does not suffer from the difficulties which prevent the development of a simple intuitive picture in the commonly used sum-over-states expressions (i.e., strong interference effects and unphysical size scaling of various contributions). Displaying the CEO in real space provides an intuitive picture of the origin of the nonlinear response and the scaling and saturation of (0) for large sizes. I. Critical Survey of Quantum Computational Techniques in Molecular Engineering The design of new molecules with large optical no...

La microscopie electro-optique est une nouvelle technique de cartographie quantitative micrometri... more La microscopie electro-optique est une nouvelle technique de cartographie quantitative micrometrique des champs electriques et des composantes du tenseur electro-optique d'un milieu. Techniquement, il s'agit de mesurer le dephasage engendre par effet Pockels au moyen d'un microscope confocal inclus dans un interferometre en detection homodyne. L'echantillon doit etre transparent, non lineaire quadratique et soumis a un champ electrique, intrinseque ou applique. Cette these presente tout d'abord une etude theorique de la microscopie electro-optique. On y decrit la realisation pratique du microscope. Les resultats obtenus sur un premier echantillon en couche polymere sont ensuite etudies et on presente la premiere mesure de dephasage par effet Pockels dans une membrane phospholipidique dopee. Les perspectives d'applications a des mesures de potentiels transmembranaires sont presentees. Les difficultes technologiques qui seront rencontrees sont detaillees et des...

The invention relates to a multilayer structure comprising -a dielectric substrate (1), -a bondin... more The invention relates to a multilayer structure comprising -a dielectric substrate (1), -a bonding layer (4) extending on a first side of the dielectric substrate (1) -at least one precious metal layer ( 3.31) on said bonding layer (4), said bonding layer (4) comprising a derivative of an alkylsilane compound characterized in that the precious metal layer is established by evaporation or sputtering of said precious metal. The invention also relates to a method of manufacturing such a device is based on an electron beam lithography, optical exposure or nanoimprinting.

Optics Express

We report a detailed investigation on the second harmonic generation (SHG) emission from single 1... more We report a detailed investigation on the second harmonic generation (SHG) emission from single 150 nm diameter non-centrosymmetric gold nanoparticles. Polarization-resolved analysis together with scanning electron microscopy images shows that these nanostructures exhibit a unique polarization-sensitive SHG that depends strongly on the particle's shape. An analytical approach based on multipolar analysis is introduced to link SHG properties to the nanoparticles' shape. Those multipolar modes can be probed using polarization-resolved SHG. This multipolar analysis offers a physical picture of the relation between shape (size, symmetries, defects, etc.) and nonlinear polarized optical efficiency.

Journal of Optics, 2016

The electromagnetic field near the focus of a perfect imaging system is calculated for different ... more The electromagnetic field near the focus of a perfect imaging system is calculated for different multipolar sources that play an important role in the radiation of nanostructures. Those multipoles are the exact and extended multipoles occurring in electrodynamics. The theory of diffraction of vector waves is reviewed rigorously for a dipolar radiation and applied to the imaging of multipolar sources. Different geometries are considered in order to connect with experiments and the multipolar spread functions are given in a ready-to-use format up to the octupolar order, in the general case and in the paraxial approximation. Defocus imaging is finally considered to provide a first step toward multipolar imaging.

The Journal of Physical Chemistry C, 2016

Journal of Optics, 2015

Gold is one of the most widely used metals for building up plasmonic devices. Although slightly l... more Gold is one of the most widely used metals for building up plasmonic devices. Although slightly less efficient than silver for producing sharp resonance, its chemical properties make it one of the best choices for designing sensors. Sticking gold on a silicate glass substrate requires an adhesion layer, whose effect has to be taken into account. Traditionally, metals (Cr or Ti) or dielectric materials (TiO2 or Cr2O3) are deposited between the glass and the nanoparticle. Recently, indium tin oxide and (3mercaptopropyl)trimethoxysilane (MPTMS) were used as a new adhesion layer. The aim of this work is to compare these six adhesion layers for surface-enhanced Raman scattering sensors by numerical modeling. The near-field and the far-field optical responses of gold nanocylinders on the different adhesion layers are then calculated. It is shown that MPTMS leads to the highest field enhancement, slightly larger than other dielectric materials. We attributed this effect to the lower refractive index of MPTMS compared with the others.

Nanoscale, 2016

Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenom... more Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised "click" reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the "click" chemistry.

2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, 2006

ABSTRACT

ABSTRACT We have studied the Surface-Enhanced Raman Scattering (SERS) of shape controlled metalli... more ABSTRACT We have studied the Surface-Enhanced Raman Scattering (SERS) of shape controlled metallic nanoparticles: nanocylinders and nanowires, designed through electron beam lithography and lift off techniques. We have notably studied the influence of Localized Surface Plasmon Resonance (LSPR) on the efficiency of SERS. We will demonstrate that the nanowires have specific enhancement behavior and can actually act as nano-antenna.

Applied Physics Letters, 2015

Le projet REMANTAS propose de developper un capteur pour rendre possible l’analyse de contaminant... more Le projet REMANTAS propose de developper un capteur pour rendre possible l’analyse de contaminants sur sites terrestres, cotiers ou maritimes. Les polluants cibles, HAP, COV, BTEX, sont inscrits a la liste de la DCE ou font partie des substances candidates et/ou font partie des 100 substances les plus transportees par voie maritime. Ces trois familles de contaminants permettent de montrer l’adaptabilite du capteur en vue d’elargir le champ d’application de la technique d’analyse sur site. Les limites de detection visees sont du meme ordre de grandeur que celles des techniques de reference.

AIP Conference Proceedings, 2010

ABSTRACT This study describes the effect of the surrounding medium on the SERS efficiency using n... more ABSTRACT This study describes the effect of the surrounding medium on the SERS efficiency using nanolithographied substrates on which Polycyclic Aromatic Hydrocarbons are investigated. We will show that the optimum nanocylinder size is shifted to lower diameter by increasing the dielectric constant of the liquid medium. This rule is discussed in terms of Localized Surface Plasmon Resonance since its position influences directly SERS intensity. This study is done for two excitation wavelengths: 632.8 nm and 785 nm. The aim of this work is collect information in order to product future active SERS sensors suitable for in situ environmental analysis.