A novel process for the fabrication of Long Range Surface Plasmon Polariton (LRSPP) waveguide based biosensors is presented herein. The structure of the biosensor is comprised of Au stripe waveguide devices embedded in thick CYTOP claddings with a SiO2 solvent diffusion barrier and etch-stop layer. The SiO2 layer is introduced to improve the end quality of Au waveguide structures, which previously deformed during the deposit of the upper cladding process and to limit the over-etching of CYTOP to create micro-fluidic channels. The E-beam evaporation method is adapted to deposit a thin SiO2 on the bottom cladding of CYTOP. A new micro-fluidic design pattern is introduced. Micro-fluidic channels were created on selective Au waveguides through O2 plasma etching. The presented data and figures are refractive index measurements of different materials, thickness measurements, microscope images, and AFM images. Optical power cutback measurements were performed on fully CYTOP-cladded symmetric LRSPP waveguides. The end-fire coupling method was used to excite LRSPP modes with cleaved polarization maintaining (PM) fibre. The measured mode power attenuation (MPA) was 6.7 dB/mm after using index-matched liquid at input and output fibre-waveguide interfaces. The results were compared with the theoretical calculations and simulations. Poor coupling efficiency and scattering due to the SiO2 are suspected for off-target measurements.

Les nano-antennes optiques permettent la manipulation, le confinement et l'exaltation des champs électromagnétiques dans des volumes sub-longueur d'onde. Les applications de ces nano-objetsconcernent des domaines variés tels que les nano-sources de lumière,la photovoltaïque, la microscopie, la spectroscopie... Les propriétés physiques de ces nano-antennes dépendant essentiellementde leur nature, leurs tailles et leurs géométries, lacaractérisation expérimentale de ces nano-objets est essentielle car elle permet d'en améliorer fortement le design et d'amplifier les réponses électromagnétiques.La problématique de ce travail de thèse concerne la caractérisation et l'exploitation des propriétés de nano-antennes optiques. Différentes techniques de caractérisation expérimentale de nano-antennes ont été développées au cours de cette thèse: spectroscopie de corrélation de fluorescence, suivi de dynamique temporelle de boîtes quantiques, spectroscopie sous saturation de fluorescence. Ces techniques ont été appliqués pour étudier différents types d'antennes optiques: microsphères diélectriques, nano-ouvertures simples et nano-ouvertures corruguées. Réciproquement, ces nano-antennes optiques ont été utilisées pour améliorer efficacement la détection de molécules fluorescentes en solution, avec des exaltations de fluorescence moléculaire supérieures à un facteur 100 et un contrôle de la directivité d'émission de fluorescence, ouvrant ainsi de nouvelles opportunités en biophotonique. / Optical nanoantennas allow manipulation, confinement and enhancement of light in sub-wavelength volumes. The applications of these nano-objects are related to various fields such as nano-lightsources, photovoltaic, microscopy, spectroscopy... The physical properties of these nanoantennas depending mainly on their nature,sizes and geometries, the experimental characterization of thesenano-objects is essential because it allows to improve significantly their design and amplify the electromagnetic responses.The focus of this work concerns the characterization and exploitationproperties of optical nanoantennas. Several experimental characterization techniques of nanoantennas have been developedduring this thesis: fluorescence correlation spectroscopy FCS,temporal dynamics monitoring of quantum dots, spectroscopy bysaturated excitation of fluorescence. These techniques were appliedto study different types of optical antennas: dielectricmicrospheres, bare nanoapertures and corrugated nanoapertures. Theseoptical antennas have been used to effectively improve the detectionof fluorescent molecules in solution, with fluorescence enhancementgreater than a factor of 100, together with a directivity control ofthe fluorescence emission, opening new opportunities inbiophotonics.

The diploma thesis is aimed to excitation and detection of surface plasmon polaritons by visible light. First of all, we will briefly remind some basic principles like waves, electromagnetic wave, light on the interface and optical properties of metals. By using these principles we show presence of surface plasmon polaritons states. After the explanation of their properties there will be clearly visible reasons for aplications of the special excitationand detection methods. We will describe especially the prism coupling, periodic grating coupling and SNOM. Two last sections deal with computer simulations and experiments related to these methods. This means we can exemplify some knowledge presented in previous chapters. Results of simulations are compared with the experiment where we study the excitations of surface plasmon polaritons by periodic grating on aluminium surface.

The diploma thesis deals with plasmonic nanostructures for visible eventually near-infrared region of electromagnetic spectrum. At first, there are discussed basic terms which are necessary for description of plasmonic nanostructures and their properties. Then the resonant properties of gold nanoantennas on a fused silica substrate and in proximity of nanocrystalline diamond are addressed. FDTD simulations are used for an assesment of resonant properties and local electric field enhancement of these nanostructures. Possible manufacturing methods of the antennas and techniques for the measurement of their properties are mentioned at the end of the thesis.

Far-field optical spectroscopy allows for measurement of plasmonic resonances on metallic nanostructures of various shapes and sizes when illuminated by continuous light. Employing dark-field microscopy makes it possible to measure scattering on a localised plasmon excited on a single, isolated nanostructure. For the purpose of these measurements an apparatus based on commercial dual microscope system Nanonics has been put together. Experiments carried out during work on this thesis have shown a great sensitivity of the apparatus in its present form, allowing to measure a plasmonic resonance of a single nanoparticle. Proposed improvements of the apparatus should lead to even greater sensitivity and precision of measurements in the near future.

Two rich and vibrant fields of investigation - graphene and plasmonics - strongly overlap in this work, giving rise to a novel hybrid photodetection device. The intrinsic photoresponse of graphene is significantly enhanced by placing the gold nanorods exhibiting unique anisotropic localized surface plasmon resonances on the graphene surface. The reported enhanced photoresponse of graphene is caused by the redistribution of localized surface plasmons in the nanoparticles into graphene. The exact underlying energy redistribution mechanism is thoroughly studied by a single particle scattering spectroscopy monitoring the particle plasmon linewidth as a function of the number of underlaying graphene layers. The obtained extraordinary plasmon broadening for nanoparticles placed on graphene suggests the contribution of a novel energy redistribution channel attributed to the injection of hot electrons from gold nanorods into graphene.

Ce travail concerne le développement d’un nouveau type de microscopie optique en champ proche (SNOM) basé sur la mise en œuvre de sondes dite actives qui utilisent le signal de génération de seconde harmonique (SHG) d’un petit nombre de molécules orientées. L’orientation de ces molécules est obtenue par l’application d’un champ électrique statique dans une jonction constituée d’une pointe métallique effilée placée à proximité d’un substrat conducteur et immergée dans une solution de molécules dipolaires non-linéaires. L’excitation laser de ces molécules localement orientées permet d’obtenir une polarisation non-lineaire à fréquence double qui constitue une nanosource de lumière intrinsèquement localisée et pouvant interagir avec le champ proche du substrat. Nous nous sommes intéressés à l’imagerie de nano-objets lithographiés par cette technique de SNOM-SHG. Nous avons pu démontrer la possibilité d’obtenir une résolution de l’ordre de 200 nm, soit une résolution meilleure d’un facteur 2 par rapport à la limite de diffraction.Nous avons ensuite étudié les moyens d’optimiser les performances de ce nouveau type de sondes SNOM-SHG. Une voie consiste à exploiter les propriétés d’antenne optique de pointes métalliques effilées, qui peuvent être le siège d’effets d’exaltation du champ électromagnétique résultant de la singularité géométrique de ces objets (extrémité effilée) ou de l’excitation de résonances plasmons. Afin de pouvoir quantifier ces effets, nous avons entrepris la caractérisation, par luminescence à 2 photons (TPL), de nanofils d’or considérés comme objets de référence pour mimer une pointe. Des fils lithographiés ainsi que des fils issus de chimie colloïdale ont été étudiés de façon à mieux comprendre à la fois l’influence de la forme et de la cristallinité des objets sur les exaltations de champ. Des études simultanées de la géométrie et des propriétés optiques d'un nanofil unique ont été menées au moyen d'un microscope optique inversé associé à une excitation laser et couplé à un microscope à force atomique (AFM) dont la pointe est préalablement réglée pour coïncider avec le spot laser. En balayant l’échantillon, nous pouvons directement confronter l’image topographique de l’objet à la cartographie de points chauds enregistrés à sa surface, le signal de TPL étant directement corrélé à la densité locale d’états électromagnétiques. Nous avons pu montrer que les fils lithographiés et les fils colloïdaux présentaient des facteurs d’exaltation locale de champ différents, la cristallinité des objets pouvant aussi être révélée que via l’analyse spectrale du signal de TPL émis. Enfin, un dernier volet important de mon travail a consisté à faire évoluer le banc expérimental précédemment développé au laboratoire de façon à pouvoir réaliser simultanément des caractérisations de type SNOM-SHG et des caractérisations topographiques. Dans ce but, nous avons travaillé à l’intégration d’une tête AFM diapason sur notre banc de microscopie non-linéaire. Au-delà des aspects électroniques liés à l’optimisation du fonctionnement de ce diapason, le couplage du faisceau laser dans le microscope a également été entièrement reconfiguré. / This work deals with the development of a new kind of scanning near-field optical microscopy (SNOM) based on the realization of so-called active probes taking advantage of the second harmonic generation (SHG) signal coming from a few oriented molecules. The orientation of these molecules is obtained by applying a static electric field in a junction made of a sharp metallic tip placed close to a conductive substrate and immersed in a solution containing dipolar non-linear molecules. A second order nonlinear polarization is obtained from these locally oriented molecules following their excitation with a laser beam finally leading to a nanosource of light intrinsically localized and able to interact with the near-field of the substrate.We have investigated this SNOM-SHG technique to image nano-objects made by e-beam lithography. We were able to demonstrate that a resolution of about 100 nm could be reached, which appears better (of a factor2) than the diffraction limit.We have then been focusing on the way to improve the capabilities of this new type of SNOM-SHG probes. One approach consists in taking advantage of the optical antenna effects that can occur at the end of sharp tips, where the electromagnetic field can be enhanced due to geometrical effects (sharp extremities) or due to the excitation of plasmon resonances. In order to quantify these field enhancements, we have carried out the characterization of gold nanowires using two-photon luminescence (TPL) ; considering these wires as reference objects that can mimic tips. Nanowires made by e-beam lithography and nanowires synthesized by colloidal chemistry have both been studied in order to have a better understanding of the influence of the shape and the crystallinity on the field enhancements. Simultaneous analysis of the geometry and the optical properties of a single nanowire has been carried out using an inverted microscope associated to a laser excitation and coupled to an atomic force microscopy (AFM) which tip is previously aligned with the laser spot. When scanning the sample, we can directly correlate the topographic image of the object to the mapping of the hotspots recorded on its surface, the TPL signal being directly linked to the electromagnetic local density of states. We were able to evidence that both nanowires made by e-beam lithography or synthesized by colloidal chemistry exhibit different field enhancement factors, the crystallinity of the objects being also revealed following the spectral analysis of the emitted TPL signal.Finally, a last important part of my work has dealt with the evolution of the experimental setup previously developed in the laboratory in order to be able to achieve simultaneously SNOM-SHG type and topographic characterizations. We have therefore been working on the integration of an AFM tuning fork head to our nonlinear optical bench. Above the electronic aspects related on the optimization of the tuning fork implementation, the coupling of the laser beam in the microscope has also been reconfigured.

L’étude de phénomènes thermiques à l’échelle microscopique peut s’avérer compliquée à mettre en place, principalement à cause de l’absence de technique de mesure de température fiable. Dans ce contexte, une technique de mesure de température appelée TIQSI a été développée au sein de l’Institut Fresnel. Dans l’objectif d’étudier des phénomènes thermo-induit à l’échelle microscopique, j’ai monté un microscope capable de contrôler et de quantifier une élévation de température à l'aide de TIQSI et de nanoparticules d’or. Différents phénomènes ont ainsi pu être étudiés.La synthèse hydrothermale regroupe les réactions chimiques utilisant de l’eau liquide à des températures plus élevées que la température d’ébullition. L’utilisation de nanoparticules permet d’avoir de l’eau liquide à des températures supérieures à 100°C (état métastable). J’ai pu ainsi effectuer des réactions de synthèse hydrothermale sans autoclave ce qui constitue un nouveau concept en chimie de synthèse.Une cellule vivante peut-être endommagée par un stress de chaleur ce qui peut détériorer ses protéines. En réponse à ce stress, la synthèse de HSP permet la réparation des protéines endommagées. J’ai pu étudier la dynamique de réponse des HSP ce qui a permis d’illustrer l’intérêt d’une chauffe locale et de TIQSI pour ce genre d’expérience.Une autre application mêlant le surchauffage de l’eau liquide et la biologie a été abordée. Les organismes hyperthermophiles vivent à de très hautes températures (80-110◦C). J’ai pu durant mes expériences observer le déplacement d’hyperthermophiles. Cette avancée constitue les prémices d’expériences plus ambitieuses comme l’étude de l’interaction entre hyperthermophiles. / Nowadays, thermal experiments at the microscopic scale remain challenging to conduct due to the lack of reliable temperature measurment techniques. To solve these problems, a label-free temperature measurement technique called TIQSI has been developed in the Institut Fresnel.With the objective to study new thermal-induced effects on the microscale using TIQSI, I built a microscope aimed to control heat diffusion on the microscale using nanoparticle. Thus, I could study different phenomena in chemistry and biology.Hydrothermal methods in chemical synthesis rely on the use of superheated liquid water as a solvent. It has been shown that gold nanoparticles can be used superheated water in a metastable state. I managed to conduct hydrothermal chemistry experiments using thermoplasmonics without autoclave which represents a new paradigm in chemistry.A living cell can be damaged by a heat stress which can misfold its proteins. To response to this stress, the HSP synthesis enables the reparation of misfolded proteins. I could study the heat stress response of HSP at short time scale which allowed me to illustrate the interest of using TIQSI and a local heat.As an application mixing superheating water and biology, I studied organisms that are able to live at high temperature (80-110°C) namely hyperthermophiles. Motion of these organisms has been studied without autoclave which paves the way to more sophisticated experiments such as the interaction between hyperthermophiles.

Recent advances in nanoscale characterization and device fabrications have opened up opportunities for layered semiconductors in nanoelectronics and optoelectronics. Due to strong confinement in monolayer thickness, physical properties of this materials are greatly influenced by parameters such as strain, defects, and doping at the nanoscale. Therefore, understanding the effect of this parameters on layered semiconductors is the prerequisite for any device application. In this doctoral thesis, impact of such parameters on the optical properties of layered semiconductors are studied in nanoscale. MoS2, the most famous transition metal dechalcogenide (TMDC) (n-type semiconductor), and p-type GaSe, a member of metal monochalcogenide (MMC) are investigated in this work. Finally, in outlook, a device made of p-type few layer GaSe and n-type 1L-MoS2 is discussed.

Metallische Nanostäbe mit einer Länge im Mikrometer-Bereich wirken als Antennen für infrarotes Licht: Indem unter Lichteinfall eine kollektive Schwingung der Leitungselektronen angeregt wird (ein sogenanntes Plasmon), wird das elektrische Feld an den Stabenden stark konzentriert. Besonders starke Feldkonzentrationen treten auf, wenn zwei Antennenarme durch eine schmale Lücke getrennt sind (Dimerantenne). Somit können die Antennen Licht-Materie-Wechselwirkungen -- wie beispielsweise die Absorption infraroten Lichtes von Molekülen -- verstärken. Dieses als oberflächenverstärkte Infrarotabsorption (SEIRA) bezeichnete Phänomen ist sehr nützlich, um Signale in der Infrarotspektroskopie zu verstärken. Diese Arbeit widmet sich der effizienten Herstellung von metallischen Nanostäben für SEIRA. Im ersten Schwerpunktthema werden Dimerantennen, die per Elektronenstrahllithographie (EBL) hergestellt wurden und eine auflösungsbegrenzte Lücke aufweisen, durch eine photochemische Reduktion von Metallsalzkomplexen nachträglich vergrößert. Dadurch verringert sich die Lückengröße und erreicht Werte deutlich unter der Auflösungsgrenze der EBL. Es wird gezeigt, dass diese photochemische Abscheidung die IR-optischen Eigenschaften der Dimerantennen durch plasmonische Kopplung entscheidend verändert. Zudem steigt die Infrarotabsorption von in der Lücke befindlichen Molekülen mit sinkender Lückengröße. Im zweiten Schwerpunktthema liegt der Fokus auf der günstigen Fabrikation einer Vielzahl von IR-Antennen in einem parallelen Prozess. Dabei werden poröse Template aus anodisiertem Aluminiumoxid (AAO) als Negativ für die herzustellenden Metallstäbe benutzt. Es wird zuerst gezeigt, dass die Poren des Templates durch die photochemische Reduktion von Goldsalzkomplexen befüllt werden können. Für eine gezielte Einstellung der Stäbchenlänge und die Generierung einer nanoskaligen Lücke wird weiterhin die elektrochemische Befüllung der Template untersucht. Die hiermit hergestellten IR-Antennen werden vereinzelt, auf ein Substrat aufgetragen und hinsichtlich ihrer Struktur und ihrer IR-optischen Eigenschaften charakterisiert. Die Vor- und Nachteile der untersuchten Herstellungsmethoden und ihre Eignung für die Fabrikation von IR-Antennen für SEIRA werden diskutiert. / Metallic nanorods with lengths in the micrometer regime act as antennas for infrared light: As incident light excites a collective oscillation of the conduction electrons (a so-called plasmon), the electric field is concentrated at the rod ends. In case two antenna arms are separated by a small gap (dimer antenna), a particularly high field concentration occurs. Thereby the antennas are capable of enhancing light-matter-interaction -- for example the absorption of infrared light by molecules. This phenomenon, termed as surface enhanced infrared absorption (SEIRA), is very useful to enhance absorption signals in infrared spectroscopy. This thesis attends to the efficient fabrication of metallic nanorods for SEIRA. The first topic in focus is the manipulation of dimer antennas fabricated by electron beam lithography (EBL), featuring a gap of resolution-limited size. By applying a photochemical reduction of metal salt complexes in solution, the dimer arms are subsequently enlarged. Thereby the gap size is reduced and reaches values clearly below the resolution limit of EBL. It is shown that the IR optical properties of dimer antennas dramatically change during photochemical metal deposition. This is due to plasmonic coupling. Additionally, the absorption of infrared light by molecules located in the gap increases with decreasing gap size. The second topic in focus is the cheap fabrication of a large number of IR antennas in a parallel process. Here, porous templates of anodized aluminum oxide (AAO) are used as a negative for the metal rods to be fabricated. Firstly, it is shown that the pores of the template can be filled by photochemical reduction of gold salt complexes. For a targeted adjustment of the rod lengths and the generation of a nanoscale gap, secondly, the electrochemical filling of acsu AAO is investigated. The IR antennas prepared by this method are extracted from the template, transferred to a substrate, and individually characterized in terms of their structure and IR optical properties. Advantages and drawbacks of the fabrication methods investigated in this work as well as their applicability to the fabrication of IR antennas for SEIRA are being discussed.