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In this dissertation, I have verified that the striking purple color of the intermetallic compound AuAl₂, also known as purple gold, originates from surface plasmons (SPs). This contrasts to a previous assumption that this color is due to an interband absorption transition. The existence of SPs was demonstrated by launching them in thin AuAl2 films in the Kretschmann configuration, which enables us to measure the SP dispersion relation. I observed that the SP energy in thin films of purple gold is around 2.1 eV, comparable to previous work on the dielectric function of this material. Furthermore, SP sensing using AuAl₂ also shows the ability to measure the change in the refractive index of standard sucrose solution. AuAl₂ in nanoparticle form is also discussed in terms of plasmonic applications, where Mie scattering theory predicts that the particle bears nearly uniform absorption over the entire visible spectrum with an order magnitude higher than a lightabsorbing carbonaceous particle. The second topic of this dissertation focuses on plasmon enhanced fluorescence in gold nanoparticles (Au NPs). Here, I investigated the distance-dependent fluorescence emission of rhodamine green 110 fluorophores from Au NPs with tunable spacers. These spacers consist of polyelectrolyte multilayers (PEMs) consisting of poly(allylamine hydrochloride) and poly(styrene sulfonate) assembled at pH 8.4. The distance between Au NPs and fluorophores was varied by changing the ambient pH from 3 to 10 and back, which causes the swelling and deswelling of PEM spacer. Maximum fluorescence intensity with 4.0-fold enhancement was observed with 7-layer coated Au NPs at ambient pH 10 referenced to pH 3. The last topic of this dissertation examines a novel approach to assemble nanoparticles, in particular, dimers of gold nanospheres (NSs). 16 nm and 60 nm diameter NSs were connected using photocleavable molecules as linkers. I showed that the orientation of the dimers can be controlled with the polarization of UV illumination that cleaves the linkers, making dipolar patches. This type of assembly provides a simple method with potential applications in multiple contexts, such as biomedicine and nanorobotics. / PHD / This dissertation covers three related topics. The first is an investigation of the optical properties of the unusually colored purple gold, which is a blend of gold and aluminum with the chemical formula is AuAl₂. This compound is interesting in that the origin of this color is different from most other metals. In the case of gold, for example, the metal gold is yellow color by absorbing the blue component from white light, leaving behind yellow color reflected light. The blue light is absorbed by electrons that change their state from a lower energy to a higher one. In purple gold, the color results from a different phenomenon known as “surface plasmons.” Surface plasmons are waves consisting of many electrons that move back and forth near an interface between a metal and an electrical insulator. The energy of surface plasmons in purple gold is low and corresponds to the purple color in this compound. Recently, published theoretical work supports the possibility of surface plasmons in purple gold. In this dissertation, I experimentally verify the presence of surface plasmons in purple gold. To launch surface plasmons, light was reflected off of a purple gold film deposited on the hypotenuse of a prism with varying angles of incidence. Surface plasmons can be observed by the sudden dimming of reflected light. From this, I was able to extract the surface plasmon dispersion relation, which is the relation between the inverse of the wavelength and the energy of the surface plasmons. In addition, I computed the light absorption properties of purple v gold when it is used in a nanoparticle form. The computational result showed that small purple gold nanoparticles absorb light very well, which may be useful in photothermal cancer therapy and solar steam generation. The second dissertation topic comprises a study of fluorescent molecules. These are compounds that reemit light with a different and redder color than the color of the light that illuminates them. In this experiment, green fluorescent molecules were placed near the surface of gold nanoparticles to observe how the brightness of the light emission is affected by the distance between the molecule and the metal. The underlying mechanism is based on localized surface plasmon resonances in gold nanoparticles. Localized surface plasmon resonances are waves consisting of many electrons that oscillate inside the particle, and they only occur when light at certain frequency illuminate the particle. On the resonance, the particle also exhibits the brighter light around the particle’s surface but the dimmer light away from the particle’s surface. The light enhancement from the particle can change the light emission of the fluorescent molecules. If the fluorescent molecules were placed in the range of localized surface plasmon resonances, the light emission is increased owing to the brighter light from the particle. However, if the fluorescent molecules were placed further away from the range of localized surface plasmon resonances, the light emission is decreased owing to the dimmer light from the particle. The distance between the surface of gold nanoparticle and the fluorescent molecules was varied by wrapping the gold particles with ultra-thin films of different plastic polymers before attaching fluorescent molecules to the surface of the films. These polymer films have the property that they swell and shrink when the acidity and basicity of the solution of gold particles changes, which allows me to vary the distance between the gold particles and fluorescent molecules. The results showed that the observed light gets dimmer when the solution is more acidic. On the other hand, the brighter light is noticed when the solution is more basic, and this observation is repeatable many times. Moreover, my work differs from other published works vi in that the particles with the polymer films are more robust and stable than the other particles. This allows more design flexibility and suggests applications in biomedical or environmental research where the particles can be used to locally measure properties, such as acidity in confined spacers such as living cells. It may be possible to use this technique for tumor cells in our body or toxic pollutants in the air or water. The last dissertation topic involves assembling nanoparticles to build them into larger structures. In this experiment, I fabricated particle dimers that consisted of two gold nanospheres of different sizes. They were attached together by using small molecules that are sensitive to ultraviolet (UV) light, where these molecules allow small gold nanospheres to be attached to large gold nanospheres only in those locations on the large nanospheres that have been illuminated with a sufficient amount of UV light. To achieve this alignment, UV light with a linear polarization (a specific electric field direction) was used to select the area on the large nanospheres where the UV light was particularly intense and therefore able to break the molecules, leaving positively charged surface patches on the spheres. This results in the electrostatic attraction between the positive patches on the large gold nanospheres and the negatively charged small gold nanospheres. With this method, I was able to make dimers of nanospheres in a preferred alignment by changing the polarization of UV light. The experimental results showed a good yield of dipolar patches, which allows multifunctional nanostructures with applications in nanomedicine, optical sensing, nanoelectronics, etc.

Dans ce travail, les propriétés des réseaux diffractifs ordonnés de nanoparticules d'or sont étudiées numériquement et expérimentalement. Ces résonances sont beaucoup plus étroites que celles observées dans le cas d'une nanoparticule isolée. D'après les simulations numériques, deux régimes distincts de réponse sont identifiés, l'un correspond à l'anomalie de Rayleigh (RA) l'autre au mode plasmon de réseau 2D (LPM). Dans la partie expérimentale nous avons fabriqué des réseaux de nanoparticules d'or en utilisant la lithographie d'électronique. La transmission spectrale a été mesurée dans le domaine optique pour caractériser ces réseaux. Toutes les caractéristiques essentielles des spectres expérimentaux sont en bon accord avec les simulations numériques. Les distributions du champ électrique pour différents paramètres de réseau sont étudiées pour obtenir le maximum d'augmentation du champ à la surface de la nanoparticule. L'excitation des résonances plasmon dans les réseaux diffractifs de nanoparticules d'or en condition asymétrique de l'indice de réfraction est examinée expérimentalement. L'excitation des modes plasmon à profil spectral étroit dans l'environnement asymétrique a été expérimentalement vérifiée. La possibilité d'accorder la longueur d'onde de ces résonances dans le proche infrarouge en changeant les paramètres structurels des réseaux périodiques en combinant taille et forme des nanoparticules est discutée. Ces résultats sont importants pour les applications telles que les spectroscopies en champ électrique exalté et la détection en biologie ou en chimie. / The properties of ordered diffractive arrays of gold nanoparticles are studied numerically and experimentally. Using numerical simulations I identify, two distinct regimes of lattice response, associated with two-characteristic states of the spectra: Rayleigh anomaly and lattice plasmon mode. In experimental part gold nanoparticle arrays were fabricated using e-beam lithography. Spectroscopic transmission measurements then were carried out to optically characterize these arrays. All the essential features of the experimental spectra were reproduced well by numerical simulations. Electric field distributions for different lattice parameters are studied in order to maximize the enhancement of electric field at the nanoparticle surface. The excitation of plasmon resonances in diffractive arrays of gold nanoparticles placed in asymmetric refractive index environment is examined experimentally. The excitation of the plasmon modes with narrow spectral profile in asymmetric environment was experimentally verified. The ability to tune the wavelength of these resonances in the near infrared range by varying the structural parameters of the periodic arrays in combination with size and geometry of the constituent nanoparticles is discussed. The presented results are of importance for the field enhanced spectroscopy as well as for plasmonic bio and chemical sensing.

Les plasmons de surface (SP) sont des excitations mêlant électrons et photons localisées aux surfaceset interfaces métalliques. On peut les voir classiquement comme les modes électromagnétiquespropres d’un ensemble constitué d’un métal et d’un diélectrique. Cette thèse se base sur la capacitéofferte par les techniques de spectroscopie utilisant des électrons rapides disponibles dans un microscopeélectronique à balayage en transmission (STEM), de cartographier, dans une large gammespectrale et avec une résolution spatiale nanométrique, les modes propres SP. Une telle capacitéa été démontrée séparément, durant ces dernières années, par des expériences de spectroscopie depertes d’énergie d’électrons (EELS), qui mesurent l’énergie perdue par des électrons rapides intéragissantavec un échantillon, et de cathodoluminescence (CL), qui mesurent l’énergie réémisepar l’échantillon par l’intermédiaire de photons, toutes deux résolues spatialement. Dans le cas del’EELS, ces résultats expérimentaux sont aujourd’hui interprétables à l’aide d’analyses théoriquesconvaincantes tendant à prouver que la quantité mesurée dans une telle expérience peut être interprétéede façon sûre en terme de modes propres de surface de l’échantillon. Afin d’élargir une telleinterprétation aux techniques de spectroscopies utilisant des électrons rapides en général, j’ai effectuédes expériences combinées d’EELS et de CL résolues spatialement sur une nanoparticle uniquesimple (un nanoprisme d’or). J’ai montré que les résultats offerts par ces deux techniques présententde fortes similitudes mais également de légères différences, ce qui est confirmé par des simulationsnumériques. J’ai étendu l’analyse théorique du signal EELS au signal CL, et ai montré que la CLcartographie, tout comme l’EELS, les modes de surface radiatifs du sytème, mais avec des propriétésspectrales légèrement différentes. Ce travail constitue une preuve de principe clarifiant les quantitésmesurées en EELS et CL sur des systèmes métal-dielectriques. Ces dernières sont démontrées êtrerespectivement des équivalents nanométriques des spectroscopies d’extinction et de diffusion de lalumière. Basé sur cette interprétation, j’ai utilisé l’EELS pour dévoiler les modes propres SP demilieux métalliques aléatoires (dans notre cas, des films semicontinus métalliques avant le seuil depercolation). Ces modes propres constituent une problématique de longue date dans le domainede la nanooptique. J’ai directement identifié ces modes par des mesures et le traitement de leursrésultats. J’ai complètement caractérisé ces modes propres via les variations spatiales de l’intensitéliée à leur champ électrique, une énergie propre et un taux de relaxation. Ce faisant, j’ai montré quela géométrie fractale du milieu, dont la prédominance croit au fur et à mesure que l’on s’approchede la percolation, est responsable de l’existence de modes propres de type aléatoire à basse énergie. / Surface Plasmons (SP) are elementary excitations mixing electrons and photons at metal surfaces,which can be seen in a classical electrodynamics framework as electromagnetic surface eigenmodesof a metal-dielectric system. The present work bases on the ability of mapping SP eigenmodes withnanometric spatial resolution over a broad spectral range using spatially resolved fast electron basedspectroscopies in a Scanning Transmission Electron Microscope (STEM). Such an ability has beenseparately demonstrated during the last few years by many spatially resolved experiments of ElectronEnergy Loss Spectroscopy (EELS), which measures the energy lost by fast electrons interactingwith the sample, and CathodoLuminescence (CL), which measures the energy released by subsequentlyemitted photons. In the case of EELS, the experimental results are today well accountedfor by strong theory elements which tend to show that the quantity measured in an experiment canbe safely interpreted in terms of the surface eigenmodes of the sample. In order to broaden thisinterpretation to fast electron based spectroscopies in general, I have performed combined spatiallyresolved EELS and CL experiments on a simple single nanoparticle (a gold nanoprism). I have shownthat EELS and CL results bear strong similarities but also slight differences, which is confirmed bynumerical simulations. I have extended the theoretical analysis of EELS to CL to show that CLmaps equally well than EELS the radiative surface eigenmodes, yet with slightly different spectralfeatures. This work is a proof of principle clarifiying the quantities measured in EELS and CL,which are shown to be respectively some nanometric equivalent of extinction and scattering spectroscopieswhen applied to metal-dielectric systems. Based on this interpretation, I have applied EELSto reveal the SP eigenmodes of random metallic media (in our case, semicontinuous metal films beforethe percolation threshold). These SP eigenmodes constitute a long standing issue in nanooptics.I have directly identified the eigenmodes from measurements and data processing. I havefully characterized these eigenmodes experimentally through an electric field intensity pattern, aneigenenergy and a relaxation rate. Doing so, I have shown that the fractal geometry of the medium,which grows towards the percolation, induces random-like eigenmodes in the system at low energies.Keywords: Surface plasmons, fast electron based spectroscopies, scanning transmission electronmicroscopy, disordered media

Dans cette thèse nous avons ajouté le contrôle du paramètre spectral pour donner plus de degré de liberté à l’instrument basé sur l’Imagerie par Résonance des Plasmons de Surface (SPRI), développant un système instrumental à interrogation angulo-spectrale. Pour valider notre travail, nous avons pris comme modèle d’étude un milieu diélectrique absorbant à unelongueur d’onde visible. La fonction diélectrique complexe est traitée par le modèle de Lorentz et la relation entre la partie réelle et imaginaire de l’indice optique est assurée par la relation de Kramers-Kronig. Nous avons commencé par injecter dans la cellule de mesure un colorant absorbant à 630 nm et mesuré la réflectivité angulo-spectrale avec ce milieu. Ensuite, un programme d’ajustement, que nous avons développé, a été utilisé pour le calcul inverse et la détermination des paramètres optiques à partir des données de l’expérience. Cet ajustement permet d’extraire la partie réelle et la partie imaginaire de l’indice de réfraction démontrant la possibilité d’applications de type spectroscopique. Nous avons également intégré successivement à la surface des molécules d’ADN marquées par différents chromophores pour voir l’effet de la position d’absorption sur la variation de réflectivité angulo-spectrale. En plus des milieux absorbants, nous avons fabriqué des réseaux diélectriques et métalliques et les avons intégrés à la surface du prisme. Les structures utilisées avaient une période de 250 nm et une épaisseur de 300 nm en PMMA. Cette condition nous a permis de voir un plasmon bandgap centré à 735 nm. Cette étude expérimentale est validée par une étude théorique en utilisant la méthode RCWA pour simuler la réponse des réseaux périodiques. / During this work we added the spectral parameter to the homemade Surface Plasmon Resonance Imaging (SPRI) instrument, developing an angulo-spectral instrumental system. To validate our set-up, we first used a dielectric medium absorbing in the visible spectral range as a model case. The complex dielectric function was treated by the Lorentz model and the relationship between the imaginary and the real part of the refractive index medium was calculated with the Kramers-Kronig relation. We started by injecting an absorbing dye at 630 nm in the microfluidic cell and then measured the angulo-spectral reflectivity. The experimental measurements were fitted with calculations issued from a newly developedprogram to extract the dielectric optical parameter from the experimental data. This fit calculates the imaginary and real part of the absorbing dielectric medium demonstrating the possibility for spectroscopic applications. We also integrated DNA molecules tagged with different chromophores to study the effect of the absorption wavelength on the surface plasmon angulo-spectral reflectivity variation. Furthermore, to illustrate the interest of the spectral parameter, one can integrate adielectric or metallic grating on the prism surface. Specifically, we fabricated a dielectric grating of PMMA with 250 nm period and 300 nm thickness. We observed plasmons bandgap located at 735 nm. This experimental study was in good agreement with a simulation obtained using a RCWA method based program.

Αντικείμενο της παρούσας διδακτορικής διατριβής αποτελεί η ανάπτυξη της πειραματικής Μεθόδου Διέγερσης Επιφανειακών Πλασμονίων (Surface Plasmon Resoanance, SPR) για τη μελέτη διεπιφανειακών φαινομένων και ειδικότερα των ιδιοτήτων ισορροπίας και της κινητικής της προσρόφησης πολυμερών και ολιγομερών στη διεπιφάνεια υγρού / στερεού. Στα πλαίσια της διατριβής, κατασκευάσθηκε εξ’ αρχής πειραματική διάταξη συντονισμού επιφανειακών πλασμονίων, η οποία χρησιμοποιήθηκε για την μελέτη του φαινομένου της προσρόφησης. Παράλληλα αναπτύχθηκε θεωρητικό υπόδειγμα και υπολογιστικά εργαλεία ανάλυσης των πειραματικών μετρήσεων. Με τη χρήση της πειραματικής διάταξης μελετήθηκε η διαδικασία της προσρόφησης γραμμικών και αστεροειδών πολυμερών στη διεπιφάνεια υγρού / στερεού όπως επίσης και τασιενεργών ολιγομερών τα οποία σχηματίζουν Αυτό-οργανούμενα Μονομοριακά Στρώματα (Self Assembled Monolayers) σε επιφάνειες οξειδίου του αλουμινίου. Επιπλέον διερευνήθηκε η επίδραση της αρχιτεκτονικής των πολυμερικών αλυσίδων σε σχέση με την ικανότητά τους να αυτο-οργανώνονται σε στρώματα πολυμερικών ψηκτρών (polymer brushes). Τα πειραματικά αποτελέσματα συγκρίνονται με μετρήσεις οι οποίες έγιναν με τη μέθοδο ανάκλασης νετρονίων. Για την κατανόηση των μικροσκοπικών μηχανισμών που υπεισέρχονται κατά την αυτό-οργάνωση των πολυμερών, γίνεται χρήση θεωρητικών υποδειγμάτων κλίμακας και υπολογιστικών προσομοιώσεων Monte Carlo. Περαιτέρω, μέσω της χρήσης λεπτών στρωμάτων νανο-πορώδους αλουμίνας, προτείνεται μια νέα παραλλαγή της μεθόδου διέγερσης επιφανειακών πλασμονίων η οποία όπως αποδεικνύεται, αυξάνει την ευαισθησία της μεθόδου κατά μια τάξη μεγέθους, στην περίπτωση της ανίχνευσης της προσρόφησης ολιγομερών. Η διατριβή παρουσιάζει ολοκληρωμένα τη χρήση της μεθόδου διέγερσης επιφανειακών πλασμονίων για την αναλυτική μελέτη της προσρόφησης μορίων σε επιφάνειες. Η επέκταση της μεθόδου με τη χρήση νανο-δομημένων υλικών ανοίγει τον δρόμο για πλειάδα νέων εφαρμογών στο πεδίο της ανίχνευσης προσροφημένων μορίων από διαλύματα ιδιαίτερα χαμηλών συγκεντρώσεων. / The objective of the present PhD thesis is the development of the experimental Surface Plasmon Resonance (SPR) method, for the study of interfacial phenomena such as the equilibrium properties and kinetics of polymer and oligomer adsorption at the liquid / solid interface. For the purposes of this work a custom-made experimental apparatus has been build and used for the acquisition of SPR experimental results. A theoretical model and various computational tools were also developed for the analysis of the experimental data. With the aid of this apparatus, the adsorption process of linear and star-like polymers at the liquid / solid interface was studied together with the self-assembly of functional oligomer monolayers on alumina surfaces. In addition, the effect of different chain structure (molecular architecture) on the formation of polymer brush layers was investigated. The experimental results are compared with measurements by neutron reflectivity experiments. For the investigation of the microscopic mechanisms that are involved in the polymer self-assembly, scaling theoretical calculations and Monte Carlo computer simulations were performed. Furthermore, by the use of thin nano-porous alumina films, a new variation of the SPR method is proposed. It is demonstrated, that this improved method is characterized by over one order of magnitude higher sensitivity in the case of the detection of adsorbed oligomers. The present thesis describes in detail the use of the SPR method for the analytical study of molecular adsorption on surfaces. The improvement of the SPR technique by the use of nano-structured materials opens new prospects for many new applications in the field of molecular detection in very dilute solutions.

Surface Plasmons (SP) are elementary excitations mixing electrons and photons at metal surfaces,which can be seen in a classical electrodynamics framework as electromagnetic surface eigenmodesof a metal-dielectric system. The present work bases on the ability of mapping SP eigenmodes withnanometric spatial resolution over a broad spectral range using spatially resolved fast electron basedspectroscopies in a Scanning Transmission Electron Microscope (STEM). Such an ability has beenseparately demonstrated during the last few years by many spatially resolved experiments of ElectronEnergy Loss Spectroscopy (EELS), which measures the energy lost by fast electrons interactingwith the sample, and CathodoLuminescence (CL), which measures the energy released by subsequentlyemitted photons. In the case of EELS, the experimental results are today well accountedfor by strong theory elements which tend to show that the quantity measured in an experiment canbe safely interpreted in terms of the surface eigenmodes of the sample. In order to broaden thisinterpretation to fast electron based spectroscopies in general, I have performed combined spatiallyresolved EELS and CL experiments on a simple single nanoparticle (a gold nanoprism). I have shownthat EELS and CL results bear strong similarities but also slight differences, which is confirmed bynumerical simulations. I have extended the theoretical analysis of EELS to CL to show that CLmaps equally well than EELS the radiative surface eigenmodes, yet with slightly different spectralfeatures. This work is a proof of principle clarifiying the quantities measured in EELS and CL,which are shown to be respectively some nanometric equivalent of extinction and scattering spectroscopieswhen applied to metal-dielectric systems. Based on this interpretation, I have applied EELSto reveal the SP eigenmodes of random metallic media (in our case, semicontinuous metal films beforethe percolation threshold). These SP eigenmodes constitute a long standing issue in nanooptics.I have directly identified the eigenmodes from measurements and data processing. I havefully characterized these eigenmodes experimentally through an electric field intensity pattern, aneigenenergy and a relaxation rate. Doing so, I have shown that the fractal geometry of the medium,which grows towards the percolation, induces random-like eigenmodes in the system at low energies.Keywords: Surface plasmons, fast electron based spectroscopies, scanning transmission electronmicroscopy, disordered media

The interaction of light and matter at nanoscale is the subject of study of this dissertation. Particularly, the coupling of light to surface plasmons and their applications in the fields of spectroscopy and sensing is the focus of this work. In terms of spectroscopy, the simple reason of using light to study the chemical structures of different materials is the fact that the energy of light lies in the range of vibrational and electronic transitions of matter. Further, the ability to squeeze light to subwavelength dimensions opens up new possibilities of designing nano-optical devices. In this work we explore surface plasmons for two major applications: (i) Directivity enhanced Raman spectroscopy and (ii) Chemical/biological sensing. Here a new enhancement phenomenon has been demonstrated experimentally in regards to Raman spectroscopy. Typically, Raman enhancement is considered in terms of local fields only. Here we show the use of directive nanoantennas to provide additional enhancement of two orders of magnitude. The nanoantenna design is optimal in the sense that almost all of the scattered light is coupled into the numerical aperture of the collecting lens. It is shown that the additional enhancement from directivity pushes the sensitivity to single molecule regime. Further, the out of plane radiation and simplicity of the design makes it an ideal candidate for use with typical commercial microscope setups. Extra ordinary transmission through nanohole arrays in metallic films is studied for refractive index sensing. Bulk resolution of 6×10-7 is demonstrated by optimizing array dimensions, wavelength of operation, noise reduction and consideration of sensitivity of the detecting CCD camera. Self-assembled nanostructures are investigated for spectroscopic applications. Time dependent studies of nanorods assembled in end-to-end and side-by-side configurations are conducted. The end-to-end configuration results in higher local field enhancements whereas; the side-by-side configuration shows a reduction in local fields because of the cancellation of radial field components between the neighbouring nanorods. It should be noted that higher fields are desirable for Raman spectroscopy. Grating structures have been analysed using reduced coupled mode theory. In most cases, only three lowest order modes prove to be sufficient for accurate description of the system response. Here we present design guidelines for broadband operation and optimization of high quality factor resonators. Finally the complex reflection coefficient from arbitrary terminated nanorods has been investigated. Phase of reflection plays an important role in the determination of resonance wavelength of nanoantennas. It is shown that the localized surface plasmon resonance of nanoparticles can be considered in terms of propagating surface plasmons along a nanorod of similar geometry where the length of the nanorod approaches zero accompanied with π degrees of phase of reflection. The contributions made in this work can prove useful in the fields of analytical chemistry and biomedical sensing. The directive nanoantenna can find applications in a number of areas such as light emitting devices, photovoltaics, single photon sources and high resolution microscopy. Our work related to EOT based sensing is already approaching the resolution of commercially available refractive index sensors with the added advantage of multiplexed detection. / Graduate

L ’intérêt des nano-particules pour le domaine de l ’optique visible a été suscité lors du premier rapport rédigé par Faraday en 1857 et qui a initié les bases de la production de nanoparticules métalliques en vue de leur propriété optiques inattendues (coloration des solutions). Plus récemment, le contrôle et le guidage de la lumière basés sur l’excitation de résonance plasmon dans les nanostructures a permis beaucoup d’applications liées à la vie quotidienne et impliquant la lumière. La résonance plasmonique de structures métalliques estun phénomène essentiel qui conduit à des propriétés optiques uniques à travers l’interaction de la lumière avecles électrons libres du métal. L’excitation de la résonance plasmon localisé (LSPR) permet d’exalter localement l’énergie électromagnétique comme dans le cas des nano-antennes mais aussi d’acheminer la lumière à travers des canaux de dimensions sub-l sur de grandes distances distances grâce à l’excitation du Plasmonde Surface Propagatif (PSP). Au cours de cette thèse, nous avons étendu un algorithme existant afin de calculer la réponse optique (sections efficaces de diffusion et d’absorption) de NPs ayant une forme géométrie quelconque. Ce type de NP anisotrope (vis-à-vis de la polarisation incidente) peut présenter à la résonance plasmonique une section efficace de diffusion 25 fois supérieure à celle géométrique. De plus, une étude systématique importante a été effectuée afin d’optimiser la géométrie de tels Nps.En ce qui concerne la PSP qui est impliqué dans la transmission exaltée à travers les matrices d’ouvertures annulaires AAA, nous avons entrepris une étude systématique des propriétés de l’excitation du mode particul particulier sans coupure de ces nano - guides. Il s’agit du mode Transverse Electrique et Magnétique (TEM). Une étude numérique complète est alors effectuée pour correctement concevoir la structure avant qu’elle ne soit expérimentalement fabriquée et caractérisée. Pour palier certaines contraintes expérimentale, une structure inclinée est proposée et étudiée dans le cas d’un métal parfaitement conducteur. Nous avons démontrée numériquement et analytiquement certaines propriétés intrinsèques de la structure montrant un coefficient de d’au moins 50% d’un faisceau incident non polarisé indépendamment des conditions d’éclairage (polarisation,angle et plan d’incidence). Lorsque le mode TEM est excité, le flux laminaire de l’énergie à travers la structure présente une déviation géante sur de très petites distances inférieures à la longueur d’onde. Les résultats présentés dans cette thèse pourraient être considérés comme une contribution importante à la compréhension du phénomène de transmission exaltée basé sur l’excitation de ce type de mode guidé. / The release of the rst report by Faraday in 1857 set the foundation of the production of metal nanoparticlesand their unexpected optical properties (coloring). More recently, controlling and guiding light via plasmonicresonance in nanostructures enable a lot of applications affecting everyday life that involves light. Plasmonresonance of metallic structures is a key phenomenon that allows unique optical properties through the interactionof light with the free electrons of the metal. The excitation of Localized Surface Plasmon Resonance(LSPR) leads to turn-on large local enhancements of electromagnetic energy as within antennas or to routelight as waveguide to desired region with high transmission through the excitation of Propagating SurfacePlasmon (PSP). During this thesis, we have developed an existing algorithm in order to calculate the opticalresponse of NPs of any shape. We have especially determined the localized energy enhancement factor interm of optical response of nano-antenna. This anisotropic (polarization dependent) NPs type can feature, atplasmon resonance, scattering efciency factor higher than 25. Moreover, an important systematic study hasbeen performed in order to optimize design of such NPs.Concerning the PSP that are involved in the enhanced transmission through Annular Aperture Arrays (AAAs),we systematically study the properties of the excitation of the peculiar Transverse ElectroMagnetic (TEM) guidedmode inside such nano-apertures. A complete numerical study is performed to correctly design the structurebefore it is experimentally characterized. For reasons associated to fabrication constraints and efciency,a slanted AAA made in perfectly conducting metal is proposed and studied. We numerically and analyticallydemonstrate some intrinsic properties of the structure showing a transmission coefcient of at least 50%ofan un-polarized incident beam independently of the illumination configuration (polarization, angle, and planeof incidence). At the TEM peak transmission, the laminar flow of the energy through the structure can exhibitgiant deviation over very small distances ( ). The results presented in this thesis could be considered as animportant contribution to the understanding of the enhanced transmission phenomenon based on the excitationof guided modes