Réponses électromagnétiques de systèmes plasmoniques couplés

  • Stéphane-Olivier Guillaume

    Student thesis: Doc typesDoctor of Sciences

    Abstract

    Research carried out in recent years on the optical properties of metallic nanoparticles have shown that these properties are governed by the collective excitation of conduction electrons, namely plasmons. Their properties are highly dependent on the particles' characteristics (shape, size and material) and environment. If plasmons are important from a fundamental point of view, they also find their place in innovative technological developments in areas such as photovoltaics, biosensors, enhancement of spectroscopic signals and treatment of cancer.
    The current trend to focus on the study of electromagnetic properties of complex plasmonic systems, composed of several interacting nanoparticles, accentuates the weaknesses and the limitations of the various numerical methods used so far. To overcome these limitations, it is necessary to develop new approaches to simulate accurately and efficiently the optical properties of these complex plasmonic systems.
    It is in this context that is inscribed this thesis devoted to the development of an innovative numerical method able to calculate the response properties of coupled systems, excited by light and fast electron beams. The original approach developed in this thesis was obtained using an eigenmode-decomposition of the discrete-dipole approximation (DDA) equations. Thanks to the selection of a subset of these eigenmodes, it is possible to reduce the size of the system of equations to solve, thus reducing the computing resources needed to perform the calculation.
    To test the performance and the accuracy of the method, the scattering, absorption, extinction, electron energy-loss and cathodoluminescence spectra of various plasmonic systems have been studied.
    Date of Award17 Dec 2014
    Original languageFrench
    Awarding Institution
    • University of Namur
    SupervisorLuc Henrard (Supervisor), Yves Caudano (Jury), Philippe Lambin (President), Olivier Martin (Jury), Mathieu Kociak (Jury) & Gian- MARCO RIGNANESE (Jury)

    Keywords

    • Plasmon
    • Perte d'énergie d'électrons
    • Extinction optique
    • Couplage
    • Approximation des dipôles discrets
    • Nanoparticule

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