A diverse view of science to catalyse change

Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions

A diverse view of science to catalyse change:Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. we must value diversity not only in words, but also in actions

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CROISSANCE EPITAXIALE ET PROPRIETES OPTIQUES D'ILOTS QUANTIQUES AUTO-ASSEMBLES GE/SI(001)

ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Integration of Plasmonic Structures in Photonic Waveguides Enables Novel Electromagnetic Functionalities in Photonic Circuits

The development of integrated, compact, and multifunctional photonic circuits is crucial in increasing the capacity of all-optical signal processing for communications, data management, and microsystems. Plasmonics brings compactness to numerous photonic functions, but its integration into circuits is not straightforward due to insertion losses and poor mode matching. The purpose of this article is to detail the integration strategies of plasmonic structures on dielectric waveguides, and to show through some examples the variety and the application prospect of integrated plasmonic functions

Design of a half-ring plasmonic tweezers for environmental monitoring

International audienceAn integrated near-field plasmonic tweezers, based on two gold half-ring elements, is proposed. The device consists of a silicon-on-insulator (SOI) waveguide on which two symmetric half-ring-shaped elements are deposited. The SOI waveguide, having dimensions 500 × 220 nm, enables single mode light propagation at 1.55 μm. The structure of the half-ring plasmonic tweezers exhibits up to five design parameters: inner radius r i , outer radius r e , gap g, height h and angle ϑ. Gold permittivity is modeled by means of a Drude equation. The trapping performance is investigated by evaluating the optical force exerted on a nanoparticle having a radius of 25 nm, together with the stiffness and the trapping potential. Simulation results show that stable trapping is achieved for an input power as low as 27 mW at 1.55 μm, with a stiffness of − 4.06 fN mW − 1 nm − 1

La nanophotonique : des solutions pour des systèmes de visualisation améliorés et compactés

La nanophotonique a un rôle à jouer pour compacter, alléger et améliorer les systèmes optiques pour les applications de mobilité. Elle offre des solutions non accessibles à l’optique réfractive du fait de son caractère modulaire et de sa compatibilité avec les technologies planaires. En retour, de nouvelles problématiques scientifiques et technologiques lui sont posées, dont nous présentons ici quelques exemples : fonctionnalisation plasmonique d’écrans transparents, émetteur cohérent planaire vectorisé par des plasmons, adressage matriciel de pixels submicroniques

Gold anchoring on Si sawtooth faceted nanowires

This paper reports on the sawtooth faceting and the related gold coverage of silicon nanowires (NWs). ⟨ 111⟩-oriented Si NWs were grown on Si(111) substrates by ultra high vacuum chemical vapor deposition using the vapor-liquid-solid mechanism with a gold catalyst. We observed that gold nanoclusters are unequally distributed on the NW surface. They are mainly distributed on only three non-consecutive sidewalls corresponding to the ($11\bar{2}$), ($1\bar{2}1$) and ($\bar{2}11$) planes among the six available crystallographic {112} surfaces. In addition they are anchored on upward {111} facets. This original observation brings enhanced knowledge on the faceting mechanisms. The threefold symmetry of the facet formation and gold anchoring is supported by criteria of minimal Au/Si interfacial energy. Moreover results evidence that the selective presence of gold on the NW sidewalls affects the overall morphology due to an increased radial growth on the covered sidewalls