The effects of surface plasmon for InGaN/GaN multi-quantum wells and ZnO nanoparticles optical linear and nonlinear emission efficiency had been experimentally studied. Due to the critical design for InGaN MQWs with inverted hexagonal pits based on GaN, both contribution of surface plasmon effect and image charge effect at resonant and off resonant frequencies were experimentally and theoretically investigated. With off- resonant condition, the InGaN MQWs emission significantly enhanced by metal nanoparticles. This enhancement was caused by the image charge effect, due to the accumulation of carriers to NPs region. When InGaN emission resonated with metal particles SP modes, surface Plasmon effect dominated the emission process. We also studied the surface plasmon effect for ZnO nanoparticles nonlinear optical processes, SHG and TPE. Defect level emission had more contribution at high incident intensity. Emissions are different for pumping deep into the bulk and near surface. A new assumption to increase the TPE efficiency was studied. We thought by using Au nanorods localized surface plasmon mode to couple the ZnO virtual state, the virtual state’s life time would be longer and experimentally lead the emission enhancement. We studied the TPE phenomena at high and near band gap energy. Both emission intensity and decay time results support our assumption. Theoretically, the carriers dynamic mechanism need further studies.

This dissertation is focused on the interaction between femtosecond laser and patterned two-dimensional gold nanostructures. The sample was prepared by two different lithographic techniques, the nanosphere lithography and the electron beam lithography. Characterization was carried out with scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and UV-vis absorption spectroscopy. Femtosecond transient absorption spectroscopy was used to answer a number of fundamental questions regarding the laser-nanostructure interaction. Under a low density irradiation of a femtosecond laser, we examined the effect of the lattice crystallinity on the electron-phonon relaxation in monolayer periodic array nanoparticles prepared with nanosphere lithography. We found that the electron-phonon relaxation rate was faster in polycrystalline nanoparticles and decreases greatly in single crystalline nanospheres, which is explained by the presence of high density grain boundaries. The ultrafast laser-induced coherent phonon oscillations in patterned gold nanoparticles are also fully characterized. We studied the effect of size, shape, thickness, monitoring wavelength, and materials of the prismatic array nanoparticles on the period of their coherent phonon oscillations. In a gold nanodisk pair system, we found that the fractional change in the vibration frequency increases exponentially with decreasing the ratio of the interparticle separation to the particle diameter, which is explained by the coupling of the induced electric field in one nanodisk by the strong surface plasmon field of its pair partner. Based on the coherent phonon oscillation of gold caps on a polystyrene sphere monolayer array, a new all-optical gigahertz modulation technique is developed. Under a high density irradiation of a femtosecond laser, the melting and ablation processes can be induced in gold nanoparticles. We studied femtosecond laser induced shape and localized surface plasmon resonance band changes of gold prismatic array nanoparticles. We also observed that the femtosecond laser irradiation of the nanoprisms at the surface plasmon resonance absorption maximum can cause them to detach from the substrate and 'fly away'. Atomic force microscopy and scanning electron microscopy measurements revealed that the displaced nanoparticles are thinner and smaller than the undisplaced ones, which supports an atomic ablation mechanism.

La plasmonique hybride est un sujet d’actualité qui exploite des interactions physiques entre nano-objets métalliques et d’autres nanomatériaux. En bénéficiant des propriétés de chacun de leurs constituants, les nanostructures hybrides sont utilisées dans de nombreuses applications comme la détection d’espèces bio-chimiques. Dans cette thèse, nous présentons une nouvelle nanostructure hybride polymère/metal qui est non seulement utilisée comme nano-émetteur anisotrope qui s’avère aussi être un outil puissant de caractérisation du champ proche optique.La fabrication de cette nouvelle nanostructure est basée sur une approche de par photopolymérisation à l’échelle nanométrique. Cette technique, en comparaison aux méthodes traditionnelles de caractérisation, ne fournit pas seulement l’image de la distribution du champ, mais permet aussi des mesures quantitatives des plasmons de surface avec une résolution sub -5nm, incluant une description fine de la décroissance exponentielle des ondes évanescentes impliquées.A l’aide du mode plasmon dipolaire, une distribution anisotrope de matériau organique est intégrée dans le voisinage de la nanoparticule métallique. Avec une haute concentration de molécules de colorant dans le polymère, l’intensité des signaux de fluorescence et Raman du nano-émetteur hybride dépend de la polarisation incidente. À notre connaissance, il s’agit de la première réalisation d’un nano-émetteur dont le milieu à gain présente une distribution spatiale complexe le rendant sensible à la polarisation / Hybrid plasmonics has given rise to increasing interest in the context of the interaction between metal nano-objects and other materials. By benefiting from each of its constituents, hybrid nanostructures are commonly adopted in studies and optimization of biological and chemical sensors, nanoparticle with high plasmon resonance tunability, and nano-emitters. This PhD thesis presents a hybrid nanostructure of photopolymer/metal nanoparticle that is used as a near-field characterizing tool and as an anisotropic nano-emitter.The fabrication of this hybrid nanostructure is a near-field imprinting process based on nanoscale photopolymerization. This technique, compared with traditional near-field characterization methods, provides not only the image of the field distribution, but also enables quantification of the surface plasmon properties with sub-5nm resolution and reproduction of the exponential decay of the near-field.Under dipolar mode plasmon, the photopolymer was created anisotropically in the vicinity of the metal nanoparticle. With high concentration of dye molecules trapped in the polymer, the hybrid nano-emitter displays surface enhanced fluorescence and Raman signal that is dependent on the incident polarization. To our knowledge, this is the first achievement of the anisotropic nano-emitter based on the inhomogeneous distribution of the active molecule

J'ai réalisé pour cette thèse des travaux expérimentaux à l'aide de la microscopie et de la spectroscopie électronique portant sur l'étude de nanostructures plasmoniques et de nanocristaux semi-conducteurs. Le but étant d'etudier leurs propriétés optiques sur des dimensions spatiales de l'ordre du nm. A cette échelle il est possible d'observer le champs proche électrique associé aux modes de résonances plasmons de surface supportées par des nanostructures métalliques. Ainsi j'ai pu étudier l'effet de la présence de rugosités sur des nano-bâtonnets d'or et constater que leur présence modifiait localement la structure du champs proche électrique. Des mesures combinées par spectroscopie de perte d'énergie des électrons (EELS) et de cathodoluminescence ont permis de comparer les réponses mesurées en champs proches à celle effectuées en champs lointain. Une étude faite par EELS portant sur le couplage entre deux nano-bâtonnets métalliques positionnés bout à bout et séparés par une distance de quelques dizaines de nanomètres a permis de cartographier la localisation de modes hybridés séparément sur chaque branche. Enfin des études comparatives de cathodoluminescence et de photoluminescence sur des points quantiques isolés ont permis de constater l'équivalence de l'information collectées par ces deux techniques sur ce type d'émetteurs de lumière / For this thesis, I have realised some experimental works using electron microscopy and electron spectroscopies for the study of plasmonic nanostructures and semiconductor nanocrystals . The aim being to study their optical properties with spatial resolutions of the order of a few nm. At this level it is possible to observe the electric near-field associated to the localised surface plasmon resonances supported by metallic nanostructures . So I was able to study the effect due to the presence of roughness on single gold nanorods and I have found that their presence locally alterate the structure of the electric near-field . Combined measurement of electron energy loss spectroscopy (EELS ) and cathodoluminescence spectroscopy were used to compare the near-field and far-field responses respectively. A study by EELS on the coupling between two metal nanorods positioned end to end and separated by a disance of tens of nanometers was used to map the localisation of hybridised modes separately on each branch of the dimers. Finally, comparative studies of cathodoluminescence and photoluminescence on single quantum dots have shown the equivalence of the information collected by these two techniques for such light emitters

Recent experimentation with excitation of surface plasmons on a gold film in the Kretschmann configuration have shown what appears to be a superconductive effect. Researchers claimed to see the existence of electron pairing during scattering as well as magnetic field repulsion while twisting the polarization of the laser. In an attempt to explain this, they pointed to a combination of electron-electron scattering in external fields as well as dynamic screening via intense laser radiation. This paper expands upon the latter, taking a look at the properties of a dynamic polarization function, its effects on bulk and surface plasmon dispersion relations, and its various consequences.

This thesis is an attempt at studying quantum coherence effects coupled via plasmons. After introducing the quantum coherence in atomic systems in Chapter 1, we utilize it in Chapter 2 to demonstrate a new technique of detection of motion of single atoms or irons inside an optical cavity. By taking into account the interaction of coherences with surface plasmonic waves excited in metal nanoparticles, we provide a theoretical model along with experimental data in Chapter 3 to describe the modification of Raman spectra near metal nanoparticles. We show in chapter 4 that starting from two emitters, coupled via a plasmonic field, the symmetry breaking occurs, making detectable the simultaneous existence of the fast super-radiance and the slow sub-radiance emission of dye fluorescence near a plasmonic surface. In Chapter 5, we study the photon statistics of a group of emitters coupled via plasmons and by the use of quantum regression theorem, we provide a theoretical model to fully investigate the dependence of photon bunching and anti-bunching effects to the interaction between atoms, fields and surrounding mediums.

A fully oxidized state of graphene behaves as a pure insulating while a pristine graphene behaves as a pure conducting. The in-between oxide state in graphene which is the controlled state of oxide behaves as a semiconducting. This is the key condition for tuning optical band gap for the better light emitting property. The controlling method of oxide in graphene structure is known as reduction which is the mixed state of sp2 and sp3 hybrid state in graphene structure. sp2 hybridized domains correspond to pure carbon-carbon bond i.e. pristine graphene while sp3 hybridized domains correspond to the oxide bond with carbon i.e. defect in graphene structure. This is the uniqueness of the graphene-base material. Graphene is a gapless material i.e. having no bandgap energy and this property prevents it from switching device applications and also from the optoelectronic devices applications. The main challenge for this material is to tune as a semiconducting which can open the optical characteristics and emit light of desired color. There may be several possibilities for the modification of graphene-base material that can tune a band gap. One way is to find semiconducting property by doping the defects into pristine graphene structure. Other way is oxides functional groups in graphene structure behaves as defects. The physical properties of graphene depend on the amount of oxides present in graphene structure. So if there are more oxides in graphene structure then this material behaves as a insulating. By any means if it can be reduced then oxides amount to achieve specific proportion of sp2 and sp3 that can emit light of desired color. Further, after achieving light emission from graphene base material, there is more possibility for the study of non-linear optical property. In this work, plasmonic effect in graphene oxide has been focused. Mainly there are two kinds of plasmon effects have been studied, one is long range (surface) and short range (localized) plasmon. For long range plasmon gold thin film was deposited on partially reduced graphene oxide and for short range plasmon silver nanoparticles have used. Results show that there are 10-fold enhancement in light emission from partial graphene oxide coated with gold thin film while 4-fold enhancement from reduced graphene oxide solution with silver nanoparticles. Chemical method and photocatalytic method have been employed for the reduction of graphene oxide for the study of surface plasmon and localized plasmon. For the characterization UV-Vis spectrometer for absorption, spectrofluorophotometer for fluorescent emission, Raman spectrometer for material characterization, photoluminescence and time resolved photoluminescence have been utilized. Silver and gold nanoparticles are spherical of average size of 80 nm and 40 nm have been used as plasmons.

Various anomalous effects that emerge when the interfaces between media are involved in sound-matter or light-matter interactions are studied. The three specific systems examined are a fluid channel between elastic metal plates, a linear chain of metallic perforated cylindrical shells in air, and a metal-dielectric slab with the interfaces treated as finite regions of smoothly changing material properties. The scattering of acoustic signals on the first two is predicted to be accompanied by the effects of redirection and splitting of sound. In the third system, which supports the propagation of surface plasmons, it is discovered that the transition region introduces a nonradiative decay mechanism which adds to the plasmon dissipation. The analytical results are supported with numerical simulations. The outlined phenomena provide the ideas and implications for applications involving manipulation of sound or excitation of surface plasmons.