Apresentamos os resultados de preparação e caracterização de cristais orgânicos (L-arginina fosfatada monohidratada - LAP - e L-lisina monohidroclorada dihidratada - L-Lys.HCl) que possuem propriedades ópticas lineares e não lineares desejáveis para aplicações tecnológicas, incluindo telecomunicações, computação óptica, armazenamento óptico de dados, processamento óptico da imagem, conversão de freqüência, entre outras. Desenvolvemos uma metodologia, simples e barata, para a eliminação de fungos e micróbios que surgem nas soluções destes compostos devido às características dos aminoácidos L-arginina e L-lisina. A adição do fungicida azida de sódio possibilitou-nos manter soluções destes compostos livres de quaisquer microorganismos na câmara de crescimento por um período de seis meses. Usando-se as técnicas de evaporação controlada do solvente a abaixamento da temperatura grandes cristais de LAP e L-Lys.HCl foram obtidos com qualidade óptica adequada para a confecção de dispositivos optoeletrônicos. Cristais de até 6 cm&sup3 de L-Lys.HCl foram pela primeira vez preparados e caracterizados opticamente. A caracterização estrutural permitiu-nos solucionar a divergência existente na indexação do difratograma de pó dos cristais de LAP e indexar os picos de difração de raios-X da L-lisina monohidroclorada dihidratada. / Growth and characterization of organic crystal (L-arginine phosphate monohydrate - LAP - and L-lysine monohydrochloride dihydrate L-Lys. HCl) with desirable linear and nonlinear optical properties for technological application including telecommunications, optical computing, optical data storage, optical image processing, harmonic frequency generation, and others are presented. We developed a simple and cheap method to eliminate fungi and microbes that arises in solution due to characteristics of L-arginine and L-lysine aminoacids. The addition of sodium azide fungicide maintained the solutions of these compounds free of microorganisms in the growth chamber for six months. Using a accurately controlled solvent evaporation technique and slow cooling technique large crystals of LAP and L-Lys.HCI were obtained with optical quality appropriate to the development of optoelectronic devices. L-Lys.HCl crystals up to 6 cm&sup3 were growth and optically characterized for the first time. The divergence in the powder diffraction indexation of LAP crystals was eliminated by structural characterization and the X-ray diffraction peaks of the L-lysine monohydrochloride diliydrate crystals were indexed.

Orientador: Luis Eduardo Evangelista de Araujo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-17T12:16:24Z (GMT). No. of bitstreams: 1 FernandezApolinario_Ulices_M.pdf: 3294486 bytes, checksum: d7134abb4e7c7345ce3358e57af0e8db (MD5) Previous issue date: 2010 / Resumo: Nesta tese, descrevemos o desenvolvimento de um sistema laser simplificado que opera em 423 nm (baseado em um laser de diodo) e a construção de uma célula de vapor de cálcio com potencial uso em espectroscopia de alta resolução. Nosso trabalho começou com a construção de um laser de diodo em cavidade estendida operando em 846 nm e com uma potência útil de 158 mW que foi montado em configuração Littrow. Em seguida, foi duplicada a freqüência deste laser para 423 nm através de um cristal BIBO (BiB3O6), utilizado dentro de uma cavidade óptica de amplificação. A estabilização da cavidade óptica duplicadora de freqüência foi feita pela técnica de Hänsch-Couillaud para travar uma ressonância da cavidade ao laser infravermelho de entrada. Um máximo de potência de 20 mW no azul foi obtido, mas problemas relacionados ao travamento da cavidade duplicadora dificultam seu uso. Por isto, um segundo laser de diodo em cavidade estendia, similar ao anterior, mas com uma potência útil de 75 mW, foi usado com uma potência máxima de 4 mW no azul e apresentado similares dificuldades ao sistema desenvolvido anteriormente. Uma célula de vapor de cálcio foi construída tendo como fonte de átomos de cálcio um dispensador ¿Alvasource¿ da empresa ¿Alvatec¿. Uma primeira caracterização da célula através de espectroscopia de absorção foi realizada demonstrando seu potencial uso para experimentos em Física Atômica / Abstract: In this thesis, we describe the development of a simplified laser system that operates at 423 nm (based on a diode laser) and the construction of calcium vapor cell with potential use in high resolution spectroscopy. Our work began with the construction of a extended-cavity diode laser operating at 846 nm with an output of 158 mW that was mounted in Littrow configuration. Then, the laser¿s frequency was doubled to 423 nm through a BIBO (BiB3O6) crystal used within a power enhancement cavity. The stabilization of the frequency doubling cavity was made by Hänsch-Couillaud technique to lock a cavity resonance to the input infrared laser. A maximum power of 20 mW was obtained in the blue, but problems related to locking the doubling cavity hamper its use. Therefore, a second extended-cavity diode laser, similar to the above but with an output of 75 mW was tried, reaching a maximum power of 4 mW in the blue. However, it presented similar difficulties to the system developed earlier. A calcium vapor cell was constructed based on Ca ¿Alvasource¿ dispenser by ¿Alvatec¿. A first characterization of the cell by absorption spectroscopy was performed demonstrating its potential use for experiments in atomic physics / Mestrado / Ótica / Mestre em Física

Neste trabalho é feito um estudo da formatação de pulsos ultracurtos de laser de Ti:Safira para a geração de segundo harmônico em cristal de KDP. Para a formatação dos pulsos, é utilizado um aparato que inclui um modulador espacial de luz de cristal líquido (LC SLM), que altera unicamente a fase espectral dos pulsos. Este aparelho tem a vantagem de não introduzir perdas durante a propagação da luz, além de sua ação ser controlada via computador, através de um software em LabVIEW. Utilizando uma função senoidal, é feito um estudo das limitações do controle da geração do segundo harmônico provindas da pixelação do LC SLM, isto é, do fato de que os elementos moduladores possuem tamanhos finitos e produzem uma modulação discreta ao longo das componentes espectrais do pulso. É apresentada a geração de luz sintonizável em torno de 400 nm por duplicação de frequências de pulsos cuja fase espectral é modulada por uma soma de funções senoidais de frequências diferentes. A largura de banda do ultravioleta produzido é da ordem de 1 nm, em contraste com a largura de linha de cerca de 12 nm do segundo harmônico gerado na ausência de modulação do pulso fundamental. A sintonização é feita basicamente através de uma varredura na fase das funções moduladoras do pulso fundamental. Esse tipo de sintonização nessa região do espectro possui algumas aplicações, tais como a microscopia seletiva por dois fótons ou mesmo a espectroscopia de um fóton. Para comprovar a utilidade da geração de segundo harmônico sintonizável, é apresentada uma medida espectroscópica da transmissão em uma amostra de cloreto de európio, sendo que os resultados obtidos concordaram com as medidas da mesma amostra realizadas em um espectrofotômetro, com o mínimo de transmissão em cerca de 394 nm. / This work presents a study on the shaping of ultrashort pulses of a Ti:Sapphire laser for second harmonic generation in KDP crystals. To achieve the pulse shaping, a setup based on a phase-only crystal-based spatial light modulator (LC SLM) is used. This device has the advantage of low loss, and can be computer controlled, by means of a LabVIEW software. The use of a sinusoidal function, allows to study the limitations of the second harmonic generation due to the pixelation of the LC SLM, i. e., due to the fact that the modulating elements have finite sizes and produce a stepwise modulation along the spectral components of the pulse. The generation of tunable light around 400 nm by frequency doubling of laser pulses is presented for the case where the spectral phase is modulated by a sum of sinusoidal functions with different frequencies. The linewidth of the ultraviolet band produced is narrower than 1 nm, in contrast to the 12 nm linewidth of the non-modulated incident spectrum. The tuning is done primarily through a sweep in the phase of the modulating functions of the fundamental pulse. The possibility of tuning in this region of the spectrum has a few applications, such as in selective two-photon microscopy or even in one photon spectroscopy. To demonstrate the usefulness of tunable second harmonic generation, a spectroscopic measurement of the transmission in a sample of europium chloride is presented, and the results agreed with the measures of those performed in a spectrophotometer, with the minimal transmission occurring around 394 nm.

La thèse montre des solutions pour la réalisation de circuits photoniques intégrés utilisant le caractère volumétrique et les très faibles pertes en propagation des solitons spatiaux. On s'intéresse aux éléments de base : interconnexions, sources et router optique (comme dispositif d'élaboration). Interconnexions et sources sont réalisé dans le niobate de lithium (LN) qui fournis des structures avec une très longue durée temporelle. Le fonctionnement d'un router optique est démontré dans le semiconducteur photo-réactif (PR) InP:Fe en raison de sa sensitivité aux longueurs d'onde infrarouges (IR) et à son temps de réponse rapide. On montre que les pertes en propagation dans les interconnexions solitoniques peuvent être réduites à nouveau en utilisant un faisceau en polarisation ordinaire qui augmente la variation d'indice de réfraction induite. La réalisation de sources intégrées solitoniques est étudié pour avoir émission en bleu à 400nm et en IR à 1530nm. Celles en bleu sont obtenues par génération de deuxième harmonique ; le rôle du bleu pour la formation des solitons est montré et ses propriétés physiques étudiées. Celles en IR sont obtenues en dopant le LN avec des ions (actifs) d'erbium. Leurs effets sur les paramètres PR sont présentés et les solitons spatiaux sont obtenus en excitant l'absorption soit du LN soit de l'erbium. L'amplification de la luminescence est étudié numériquement. Le routage optique dans le InP:Fe est obtenu en faisant interagir deux solitons cohérents et en changeant leur phase relative. L'augmentation de la séparation ou leur fusion est analysé en fonction de la distance entre eux, température et intensité de la lumière / Solutions for the realization of integrated photonic circuits with the advantages that spatial solitons offer, like their volumetric nature and the very low propagation losses are shown. Interconnections, sources and optical router (as signal elaboration device) are investigated. Interconnections and sources are experimentally demonstrated in lithium niobate (LN) that provides long-lasting structures thanks to its very long dielectric relaxation time. The optical router working principle is realized in the photorefractive semiconductor InP:Fe because of its sensitivity in infrared radiation and its fast response time. To improve solitonic interconnections, an analysis based on propagation losses in function of light polarization and LN anisotropy is done. The key role played by an ordinary polarized beam on the induced refractive index variation is exploited. Integrated sources in solitonic waveguides for the emission of blue at 400nm and of an infrared beam at 1530nm are investigated. Sources emitting in blue are obtained via a second harmonic generation process ; blue seed role in spatial soliton formation is demonstrated and its physical properties are investigated as well. The infrared one is achieved by doping LN with (active) erbium ions. Their effects on the photorefractive parameters are exploited and spatial solitons realized both pumping direcly erbium absorption lines and the LN ones. Luminescence amplification is studied numerically. Optical routing in InP:Fe is achieved by making two coherent solitons interact by changing their relative phase. Separation increasing or fusion is analyzed in function of mutual distance, temperature and light intensity

Much of the interest in bent-core compounds in the last few years has centred aroundtheir potential to form nematic liquid crystal phases, which may be both biaxial andpolar. These properties offer possibilities for nematic ferroelectric switching andnonlinear optics applications. In this work, two optical properties, the refractive indices and the second ordernonlinear optical response, were investigated in the high temperature (> 170 °C)nematic phase of a series of bent-core oxadiazole compounds, of varying chain typeand length. An experimental technique, based on the acquisition and analysis of reflectionspectra from liquid crystal cells, and capable of operating at the high temperaturesrequired, was used for the measurement of refractive indices. The extraordinaryrefractive index was found to range from 1.70 to 1.78 over the nematic phase of thebent-core compounds. The ordinary refractive index varied from 1.58 to 1.62. Bothranges of values are higher than is typically observed for rod-like liquid crystals. Thebirefringence took values from ~ 0.10, in the high temperature nematic phase, to~ 0.18, close to the underlying smectic phase. A new experiment was designed, constructed and tested for the second harmonic(SH) measurements. The dependences of the SH on temperature and on scatteringangle are well explained by the theory of SH generation by the flexoelectricpolarisation induced by thermal fluctuations of the director in the nematic phase. Themaximum conversion efficiency was measured to be very low, ~ 1/10000 of apercent. No evidence for the formation of macroscopic biaxial nematic phases was found byeither the refractive indices or SH experiments. However, for the compounds havinglong nematic phases of > 50 °C, different regimes of behaviour in the uniaxialnematic phase were revealed by the SH experiments. This atypical behaviour isconsistent with other reports on these compounds. This study cannot confirm the existence of nanoscale cybotactic clusters in thenematic phases of the bent-core compounds examined but neither is it inconsistentwith them.

The evolution of electronics has become the staple thrust of modern scientific innovation: a need for advancing materials engineered for our equally rapidly advancing needs and computing requirements has fueled recent wealth of new materials. Here, I use the ideals of exotic materials design to answer this need, specifically for 2D materials. Two-dimensional (2D) van der Waals materials with in-plane anisotropy are of great interest for directional transport of charge and energy. I perform solid state synthesis to produce several such materials: an intrinsic antiferromagnet, superatomic semiconductors, and a polytype system with a component that displays the possibilities of Weyl nodes.The former, chromium sulfur bromide (CrSBr), is first synthesized, then fully studied structurally, compositionally, electronically, and magnetically. Second harmonic generation (SHG), more advanced than older techniques such as magneto-optical Kerr spectroscopy or Raman spectroscopy, allows us to fully understand the magnetic symmetry in this system as an interlayer antiferromagnetic and intralayer ferromagnetic in-plane anisotropic material. I also introduce published work in which we integrate CrSBr into different devices to show the utility of this fundamental research into a more practical application setting. It is used to stimulate more magnetic response from graphene — promising ultra-thin magnetic memory or sensory devices in future projects. Applying strain and external magnetic fields provides another tuning knob through which to access different functional modalities. In the latter third of this dissertation, we report a layered van der Waals semiconductor with in-plane anisotropy built upon the superatomic units of Mo₆S₃Br₆ (MSB), a robust construction with a direct gap of 1.64 eV. Next, MSB and Re₆Se₈Cl₂, another analogous superatomic vdW material, are potential candidates for optoelectronic applications; we qualify this by studying their Auger dynamics as a measure of quantum efficiency. Finally, layered van der Waals (vdW) materials belonging to the MM’Te₄ structure class have recently received intense attention due to their ability to host exotic electronic transport phenomena, such as in-plane transport anisotropy, Weyl nodes, and superconductivity. In summary, we have discovered two ternary exfoliatable vdW TMD polytypes with the composition TaFeTe₄, one of which (ꞵ) shows the prerequisite symmetry elements to be a type-II Weyl semimetal. This dissertation is a treatise to solid state synthesis, exploration into the more exotic spectrum of 2D materials, and robust and eclectic methods used to paint a full picture of different magnetic and electronic systems within.

<p>The symmetry requirements of both second harmonic generation (SHG) and triboluminescence (TL) provide outstanding selectivity to noncentrosymmetric crystals, leading to high signal to noise measurements of crystal growth and nucleation of active pharmaceutical ingredients (API) within amorphous solid dispersions (ASD) during accelerated stability testing. ASD formulations are becoming increasingly popular in the pharmaceutical industry due to their ability to address challenges associated with APIs that suffer from poor dissolution kinetics and low bioavailability as a result of low aqueous solubility. ASDs kinetically trap APIs into an amorphous state by dispersing the API molecules within a polymer matrix. The amorphous state of the API leads to an increase in apparent solubility, faster dissolution kinetics, and an increase in bioavailability. Both SHG and TL are used to quantitatively and qualitatively detect the crystal growth and nucleation within ASD formulations at the parts per million (ppm) regime. TL is the emission of light upon mechanical disruption of a piezoelectrically active crystal. Instrumentation was developed to rapidly determine the qualitative presence of crystals within nominally amorphous pharmaceutical materials in both powders and slurries. SHG was coupled with a controlled environment for <i>in situ</i> stability testing (CEiST) to enable <i>in situ</i> accelerated stability testing of ASDs. Single particle tracking enabled by the CEiST measurements provided insights into crystal growth rate distributions present due to local differences within the material. Accelerated stability testing monitored by <i>in situ</i> measurements increased the signal to noise in recovered nucleation and crystal growth rates by suppressing the Poisson noise normally present within conventional accelerated stability tests. The disparities between crystal growth and nucleation kinetics on the surface versus within bulk material were also investigated by single particle tracking and <i>in situ </i>measurements. Crystals were found to grow faster in the bulk compared to single crystals growing on the surface while total crystallinity was found to be higher on the surface due to radial growth habits of crystals on the surface compared to columnar growth within the bulk. To increase the throughput of the <i>in situ </i>measurements, a temperature and relative humidity array (TRHA) was developed. The TRHA utilizes a temperature gradient and many individual liquid wells to enable the use of a multitude of different conditions at the same time which can reduce time required to inform formulations design of stability information. </p>

The scope of this PhD-thesis is the production and characterization of highly conductive ferroelectric domain walls in 5 mol% magnesium-doped lithium niobate single crystals. Therefore one domain wall is induced into a single domain sample by the means of a local poling procedure. The produced structure is contacted through evaporated macroscopic metal electrodes. Since domain walls typically exhibit low currents a high voltage treatment is applied to persistantly increase the conductance by several orders of magnitude. A deeper understanding of the mechansimn behind the transport characteristics is given via atomic force microscopy and Cherenkov second-harmonicgeneration-microscopy. The combinaiton of surface sensitive conduction measurements and three dimensional topology detection prove to be magnificent complementary methods. A clear correlation between inclination with respect to the z-axis and local conductivity is found. Through this correllation a simple and intuitive theory is derived inside the band model, which quantitativly explains the observed behaviour. Following some key process parameters like electrode material, poling procedure and doping of the lithiumniobate crystal are varied, while their influence on the high voltage treatment is investigated. Additionally the procedure is also applied to domain walls in lithium tantalate. Lastly domain walls are observed in real time under the influence of an electric field via Cherenkov second-harmonic-generation-microscopy. There is the possibillity of either two or three dimansional investigations while the latter bears a worse time resolution. It is shown that the speed of the domain wall movement holds a gradient along the z-axis, depending on the polarity of the electric field. / Die vorliegende Dissertation behandelt die Herstellung und Charakterisierung hochleitfähiger ferroelektrischer Domänenwände in 5 mol% magnesiumdotierten Lithiumniobat-Einkristallen. Dabei kommen eindomänige Probenstücke zum Einsatz in die durch lokale Umpolung eine einzelne Domänenwand induziert wird. Die makroskopische Kontaktierung der erzeugten Struktur erfolgt mit Hilfe von aufgedampften Metallelektroden. Da die Domänenwände üblicherweise nur sehr kleine Leitfähigkeiten zeigen wird durch eine Hochspannungsbehandlung selbige nachhaltig um mehrere Gröÿenordnungen erhöht. Einen tieferen Einblick in die Mechanismen der veränderten Transportcharakteristik gewähren die Rasterkraft- und Cherenkov-Second-Harmonic-Generation-Mikroskopie. Die Kombination aus oberflächensensitiver lokaler Leitfähigkeitsmessung und dreidimensionaler Topologieerfassung erweisen sich als ausgezeichnete komplementäre Methoden. Sie zeigen eine klare Korrelation zwischen Neigungswinkel der Wand im Verhältnis zur z-Achse und der gemessenen Leitfähigkeit. Über diesen Zusammenhang wird eine einfache, intuitive Theorie der Domänenwand im Bändermodell entwickelt, die das Verhalten quantitativ erklärt. Es folgt die Untersuchung verschiedener Prozessparameter wie Elektrodenmaterial, Polungsprozedur sowie Dotierung des Lithiumniobats und deren Einfluss auf die Hochspannungsbehandlung. Zudem wird diese auch an Lithiumtantalat-Kristallen getestet. Abschlieÿend wird eine Echtzeitmessung der Domänenwand unter angelegtem Feld mittels Cherenkov-Second-Harmonic-Generation-Mikroskopie durchgeführt. Diese ist dabei in zwei bzw. drei räumlichen Dimensionen möglich, wobei letztere eine geringere Zeitauflösung besitzt. Es wird deutlich, dass die Geschwindigkeit mit der sich die Domänenwand bewegt, einen Gradienten entlang der z-Achse aufweist. Dieser ist von der Polarität des elektrischen Feldes abhängig.

Plasmonic metasurfaces enable functionalities that extend beyond the possibilities of classical optical materials and as a result, have gained significant research interest over the years. This thesis aims towards introducing plasmonic metamaterials and metasurfaces, a two-dimensional subset of metamaterials. The thesis also provides insights into the nonlinear optical responses from subwavelength metallic nanostructures manifesting as extraordinary physical phenomena like the second harmonic generation (SHG). The hydrodynamic Drude model is a theory that characterizes electron conduction in a hydrodynamic way to predict optical responses of metals. The thesis discusses the various contributions to the second-order optical nonlinearities from the terms in the hydrodynamic model: Coulomb, convection, and the Lorentz magnetic force. The significance of these terms, specifically the Lorentz magnetic term, is validated in contrast with existing research. The details of the work carried out to achieve a significant contribution to SHG from the Lorentz magnetic term are provided. A dominant Lorentz magnetic force for SHG was achieved through engineering T-shaped aperture arrays milled into a thin gold film. The dimensions of these structures were tuned for fundamental wavelength resonance. The structures exhibit both magnetic and electric field enhancements at the plasmonic resonance. Furthermore, a revised theoretical model is developed to accurately predict both linear and nonlinear optical responses of metamaterials. The model is based on the hydrodynamic Drude model and nonlinear scattering theory. Results from the finite difference time domain simulations performed on the metasurface are presented. It is observed that the T-shaped structure provides 65% greater nonlinear generation from the Lorentz magnetic term than the sum of the other two hydrodynamic terms. The influence of incident beam polarization on SHG conversion efficiency was also investigated. It was discovered that even though the contributions of hydrodynamic (Coulomb and convection) terms are maximum at 0◦ and 90◦, the metasurface shows maximum SHG intensity at 45◦ which indicates a dominant Lorentz magnetic term. Experimental validation was performed using the fabricated metasurface and a good agreement between the experiment and theoretical calculations was observed. Another aspect of the magnetic Lorentz force contribution, Bethe’s aperture theory was evaluated for a circular aperture at off-normal incident light. It is shown that the Lorentz force dominates the SHG by an order of magnitude at angled incidence where the generation is maximized. The angular dependence was observed to match the magnetic and electric dipole interaction effects as predicted from Bethe’s theory. The revised theory developed in this thesis predicts the linear and nonlinear optical responses of metamaterials including their angular dependency. The analysis and numerical calculations for a circular aperture agree well with past experiments. To conclude, the thesis provides an outlook on future developments in the field of nonlinear plasmonic research with regards to the development of highly efficient nonlinear metasurfaces through optimization of the Lorentz contributions. An insight into the recent developments in nanofabrication capabilities, design methodologies, nano-characterization techniques, modern electromagnetic simulations is discussed as avenues for future research in nanophotonic and nanoplasmonic device design and development. / Graduate

L’optique non linéaire est un outil très puissant pour l’étude des propriétés photoniques de molécules, de matériaux et de nanostructures. La taille et la forme des nanoparticules de métaux nobles (NMNPs) influencent fortement leurs propriétés optiques non linéaires du second ordre. Dans cette thèse, nous proposons une étude systématique de l'influence de la surface de nanoparticules sur leurs valeurs de première hyperpolarisabilité bêta. Des nanoparticules en poudre d’argent (de diamètres 7 nm) ainsi que des solutions colloïdales sur NMNPs -avec différentes compositions, tailles et formes -ont été synthétisés : des nanosphères d'argent (de diamètres 10 nm), des nanosphères d’or (de diamètres 3,0; 11,6; 15,8; 17,4; 20,0 et 43,0 nm), des nanobâtonnets d’or (de rapports d'aspect 1,47; 1,63 et 2,30), des nanobâtonnets d’argent (de rapports d'aspect 5,0; 6,3; 7,5; 8,2 et 9,7), des nanofleurs de platine (de diamètres 7,0; 8,0; 10,0; 14,0; 20,0 et 31,0 nm) ainsi que des nanoprismes d'or (d’une longueur de côtés de 47,5 à 112,3 nm). La diffusion harmonique de la lumière (HLS) à 1064 nm est utilisée pour étudier la génération du second harmonique des NMNPs colloïdaux, et d'en déduire leurs valeurs de première hyperpolarisabilité bêta. Pour les nanosphères et les nanorods étudiés dans ce travail, nous démontrons que leurs valeurs de bêta présentent une forte dépendance avec leur surface, qui est le paramètre dominant dans l'évolution des valeurs de bêta. Par ailleurs, la rugosité de la surface des particules ainsi que la forme des irrégularités des nanofleurs sont responsables de valeurs exceptionnellement élevées de bêta. En outre, nous démontrons expérimentalement, pour la première fois dans la littérature, que les valeurs de bêta des nanoprismes présentent non seulement une dépendance linéaire par rapport à la surface, mais sont également sensibles aux courbures des sommets du triangle. / Nonlinear optics is well known to be a highly powerful tool to investigate the photonic properties of molecules, materials and nanostructures. Size and shape of noble metal nanoparticles (NMNPs) strongly influence their second-order nonlinear optical properties. In this PhD thesis, we propose a systematic investigation of the influence of the nanoparticle surface area on their first hyperpolarizability beta values. Powdery-silver nanoparticles (diameters 7 nm) and colloidal solutions on NMNPs with different composition, sizes and shapes have been synthesized, i.e. silver nanospheres (diameters 10 nm), gold nanospheres (diameters 3.0; 11.6; 15.8; 17.4; 20.0 and 43 nm), gold nanorods (aspect ratios 1.47; 1.63 and 2.30), silver nanorods (aspect ratios 5.0; 6.3; 7.5; 8.2 and 9.7), platinum nanoflowers (diameters 7.0; 8.0; 10.0; 14.0; 20.0 and 31.0 nm) and gold nanoprisms (edge length tuned from 47.5 to 112.3 nm). Harmonic light scattering (HLS) at 1064 nm is used to investigate the second harmonic generation from colloidal NMNPs, and to infer their first hyperpolarizability tensor beta. For the nanospheres and nanorods investigated in this work, we demonstrate that their beta values display a strong dependence with their surface area, which is the dominant parameter in the evolution of beta values. Otherwise, particle surface corrugation and shape irregularities of nanoflowers are responsible for exceptionally high beta values. Moreover, we report for the first time in the literature that the beta values of nanoprisms display not only a linear dependence with respect to the surface area, but are also sensitive to the sharpness of the triangle vertices.