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Une description des différentes configurations d’interaction ayant lieu dans les matériaux usuellement employés dans le domaine acousto-optique est proposée. Un exemple d’application illustre les caractéristiques déterminantes propres à chaque fonction que permet l’interaction acousto-optique, à savoir la modulation, la déviation, le décalage en fréquence et le filtrage d’un faisceau optique. Cette thèse est plus particulièrement consacrée aux interactions acousto-optiques anisotropes dans le cristal de Paratellurite, matériau majoritairement employé pour les applications de déflexion et de filtrage de par ses qualités photo-élastiques remarquables et son large domaine de transparence optique. Ces propriétés optiques, acoustiques et acousto-optiques sont décrites en détail. Nous nous intéressons plus particulièrement aux caractéristiques de l’interaction NPM (Narrow Phase Mismatch) et TPM (Tangent Phase Mismatch), respectivement employées pour le filtrage et la déflexion. Ceci nous conduit à l’étude de la bande passante spectrale d’un déflecteur et de sa potentielle application en tant que réseau de diffraction à bande passante et périodicité spatiale modulable. Ensuite nous proposons la mise en cascade d’un déflecteur et d’un filtre dans le but de concevoir un décaleur de fréquence variable à faible décalage. Enfin, nous proposons une configuration originale pour répondre aux contraintes d’utilisation rencontrées avec l’interaction NPM pour les applications de filtrage. La conception et la réalisation d’un composant multiélectrodes à interaction double est alors présentée dans la gamme spectrale [400; 650 nm]. La configuration proposée permet à la fois de réduire de 50% l’intensité des lobes secondaires tout en homogénéisant la bande passante optique du filtre sur sa bande spectrale de travail. / The different configurations of acousto-optic interactions taking place in usual employed materials are presented. For each function (modulation, deflection, shifting and filtering), an exemple of application highlights the decisive characteristics of the component. This thesis is particularly devoted to the anisotropic interactions occuring in Paratellurite crystal. Such material is widely used for filtering and deflection applications due to its high figure of merit and also for its large optical transparency domain, from Ultra-Violet to Infra-Red. Optical, acoustical and acoustooptical properties of Paratellurite cristal are detailed. More precisely, we are interested in anisotropic interactions, in particular NPM (Narrow Phase Mismatch) and TPM (Tangent Phase Mismatch), respectively employed for Acousto-Optic Tunable Filters (AOTF) and Acousto-Optic Deflectors (AOD). This leads to the study of the optical bandwidth of a deflector with a potential application as a tunable transmissive grating beam splitter for multiple laser line separation. Then, we propose to cascade an AOTF with an AOD in order to get a wide bandwidth tunable optical low frequency shifter. Finally, we present the design and fabrication of a multi-transducer component based on dual anisotropic interaction in the visble spectral range, from 400 to 650 nm. A significative reduction of sides lobes is observed (-50%) with an homogenisation of the optical bandwidth of the filter on its spectral working range.

Over the last few decades, the use of light to control and manipulate microscopic particles has become widespread. These methods are enabling new areas of research to flourish across the physical and biological sciences. This thesis describes investigations into both optical trapping and the closely related field of optical sorting. It documents the development of a variety of new techniques. The thesis begins with a short review of optical trapping and existing methods for sorting mixtures of microscopic particles. The first half of this chapter highlights some of the reasons behind optical trapping's rapid growth in popularity. By reviewing an array of methods for sorting particles and discussing the relative merits of each, the case for optical sorting is established. The second chapter describes research into using a spatial light modulator to create three-dimensional optically trapped colloidal structures using the time-sharing technique. Limiting factors inherent in the technology are discussed in detail. The third chapter reviews a sophisticated particle-tracking software package that has proved to be a considerable success. It was developed explicitly with colloidal microscopy in mind and experimental plots produced by the software are used throughout the thesis. Experimental studies have been performed into the behaviour of microscopic particles moving under the influence of two classes of propagation-invariant beams: Mathieu beams and Bessel beams. The Bessel beam studies have been complimented by a theoretical model and have led ultimately to a new method for the static optical sorting of both solid particles and biological cells, with particular emphasis on human blood. The fifth and final chapter describes how re-configurable optical devices can be implemented to spatially separate different colloidal species. A new method for creating arbitrary optical landscapes using an acousto-optic modulator is reported. This new technique is then used to optically sort four particle species simultaneously - the first experimental demonstration of polydisperse optical fractionation. Additionally, experiments are reported that demonstrate controlled, static optical sorting using a spatial light modulator.

Orientador: Daniel Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-15T19:43:32Z (GMT). No. of bitstreams: 1 PerezRamirez_Alexander_M.pdf: 7908178 bytes, checksum: da4f2f9161aa37bf9c7ad6fba56639bb (MD5) Previous issue date: 2010 / Resumo: Neste trabalho duas cavidades laser seladas de 13CO2 de diferente capacidade de sintonia (110MHz e 200MHz) foram montadas e caracterizadas para realizar estudos de espectroscopia de absorcção fotoacústica no infravermelho (IV) e de emissão laser no infravermelho longí?nquo (IVL) mediante a técnica de bombeamento óptico de moléculas polares. Utilizamos o modelo molecular vibro-roto-torcional para moléculas tipo metanol para assim entendermos as regras de seleção e de polarização envolvidas no bombeamento óptico para realizar os estudos de espectroscopia fotoacústica e a geração e caracterização de linhas laser IVL. Medidas espectroscópicas de absorção fotoacústica de três isótopos do metanol, na fase gasosa, foram obtidas mediante o bombeamento óptico na banda de emissão 9P do laser de 13CO2 com capacidade de sintonia de 110MHz. Os isótopos utilizados foram o 13CD3OH, CD3OD e o 13CD3OD. Os espectros para o 13CD3OD são obtidos, até onde sabemos, pela primeira vez. Obtivemos um total de 36 espectros de absorção fotoacústica os quais serviram de orientação para conseguirmos, com o bombeamento destas moléculas, a geração de 7 linhas laser IVL, que foram caracterizadas quanto ao seu comprimento de onda, sua dessintonia, pressão ideal de operacão, polaridade e intensidade relativas. Duas destas linhas obtidas são linhas novas. Já, os dados de polarização relativa e de dessintonia são novos, mesmo para as linhas já conhecidas / Abstract: In this work two 13CO2 sealed-off lasers cavities with different tuning range (110 MHz and 200MHz) were mounted and characterized to realize spectroscopy studies of infrared photoacoustic absorption and of far infrared (FIR) laser emission by the optical pumping technique of polar molecules. We used the vibra-roto-torsional molecular model for like methanol molecules to understand the selection and polarization rules involved in the optical pumping to achieve the photoacoustic spectroscopic and the generation and characterization of FIR laser lines. Spectroscopic measurements of photoacoustic absorption for three methanol isotopes, in gas phase, were obtained by the optical pumping with the 9P band of the 13CO2 laser with 110MHz of tuning range. The isotopes used were 13CD3OH ,CD3OD e o 13CD3OD. The spectrums for the 13CD3OD are obtained, to our knowledge, by the first time. We have obtained a total of 36 photoacoustic absorption spectra which served as a guide to succeed, by the pumping of these molecules, generation of 7 FIR laser lines, which were characterized according to its wavelength, its offset, ideal pressure of operation, polarity and relative intensity. Two of these lines obtained are new lines. The relative polarization and offset data are new, even for the already known lines / Mestrado / Física Atômica e Molecular / Mestre em Física

L'imagerie optique des tissus biologiques est un défi du fait de la diffusion de la lumière. Pour sonder les propriétés optiques à quelques cm de profondeur, on peut coupler l'information optique des ultrasons. De cette idée sont nées les imageries acousto-optique et photoacoustique. La première repose sur la modulation de la lumière par des ultrasons balistiques. La seconde se base sur la génération d'ultrasons lors de l'absorption de lumière par un objet. Que ce soit pour l'une ou pour l'autre, l'enregistrement du signal nécessite la mesure de très faibles modulations de phase dans une figure de speckle. L'holographie dynamique est une bonne solution. En effet, les techniques interférométriques sont suffisamment sensibles pour mesurer de telles modulations et l'holographie permet de corriger la nature speckle de la lumière. Dans cette thèse nous démontrons la faisabilité de fabriquer un système d'holographie adaptative basé sur un milieu laser (Nd :YVO4). Un des grands avantages de ce type de milieu est le temps de réponse. On montrera que le rafraîchissement d'un hologramme dans notre cristal peut se faire en moins de 100 ?s, bien inférieur au temps de décorrélation du speckle (? 1ms) qui pourrait grandement perturber les techniques de détection plus lentes lors d'expériences in vivo. Trois montages sont présentés ici, le premier pour la détection acousto-optique par conjugaison de phase, le deuxième pour la détection acousto-optique par adaptation de front d'onde et enfin le troisième pour détection photoacoustique. Dans les trois cas on mesure un temps de réponse entre 15 ?s et 50 ?s, et on utilise le montage imager un échantillon. / Strong scattering properties of biological media make their optical imaging in depth a challenge. A solution to probe the local optical properties is to couple the optical information with ultrasound. Two imaging techniques were born from this idea, acousto-optic imaging and photoacoustic imaging. The first technique is based on the local modulation of light by ballistic ultrasound. The latter relies on the emission of ultrasound following the absorption of light by an object. Whether it is acousto-optic imaging or photoacoustic imaging, the recording of the the signal requires a detection system sensitive to weak phase modulation. In addition, the detection system must be compatible with a speckle pattern. Dynamic holography is a good solution. Indeed, as it is based on interferometry, it is very sensitive to small phase variations and holography can be used to correct the speckle nature of light. In this manuscript, we show the use of an holographic detection system based on a laser medium (Nd:YVO4). One of the main advantage of this type of material is the very fast response time. It will be highlighted that the recording of a hologram inside our crystal can be done in less than 100 μs, much faster than the speckle decorrelation time (≈ 1ms), which is one of the major obstacle towards in vivo imaging. Three optical setups will be presented in this manuscript. The first one is a phase conjugation setup for acousto-optic detection. The second one is a wavefront adaption setup, also for acousto-optic detection. Finally, the third setup is an adaptive vibrometry setup for photoacoustic detection. In each setups the measured response time is between 15 μs and 50 μs.

Orientador: Odilon Divino Damasceno Couto Júnior / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-28T03:39:00Z (GMT). No. of bitstreams: 1 Covacevice_AllanCassioTrevelin_M.pdf: 15137963 bytes, checksum: 6269264b01d872c4b40e0034a1575cf5 (MD5) Previous issue date: 2015 / Resumo: Neste trabalho, implementamos cálculos feitos através do método de elementos finitos no estudo de propriedades mecânicas e ópticas de microcavidades ópticas planares (POMCs) quando estas estão sob os efeitos de modulação induzidos por ondas acústicas de superfície (SAWs). Começamos resolvendo separadamente os problemas de modulação mecânica e caracterização de modos ópticos. Após isso, fundimos esses dois modelos em um terceiro, permitindo a caracterização da modulação acusto-óptica do sistema, o que nos permite também calcular as alterações induzidas nas propriedades ópticas das POMCs devido às SAWs. Concentramos nossa atenção em POMCs que possuem refletores de Bragg (DBRs) compostos por camadas de materiais fortemente piezoelétricos, como o ZnO e o LiNbO3. Mostramos que, usando em torno de 10 DBRs acima e abaixo da cavidade óptica, POMCs baseadas em ZnO/SiO2 e LiNbO3/SiO2 poderiam, em princípio, apresentar fatores de qualidade excedentes a 104. O alto confinamento de luz na cavidade permite-nos observar efeitos relacionados ao forte acoplamento fóton-fônon induzido pelas SAWs. Em particular, mostramos como a presença de SAWs confere a formação de super-redes ópticas dinâmicas induzidas acusticamente, as quais são caracterizadas pela dobradura ("folding") da dispersão dos fótons na cavidade, e pelo surgimento de "mini" zonas de Brillouin. Nossos resultados estão de acordo com resultados experimentais presentes na literatura. Eles abrem a possibilidade de caracterização de modulações acusticamente induzidas em sistemas de camadas arbitrários e criam uma plataforma muito boa para interpretação de resultados experimentais / Abstract: In this work, we implement finite element method calculations to study the mechanical and optical properties of planar optical microcavities (POMCs) under the strain modulation induced by surface acoustic waves (SAWs). We start by solving separately the problems of mechanical modulation and optical mode characterization. Afterwards, we merge the two models in a single one which enables the characterization of the acousto-optic modulation in the system and allows us to calculate the SAW induced modification in the optical properties of POMCs. We concentrate our attention in POMCs which have distributed Bragg reflectors (DBRs) composed of layers of highly piezoelectric materials like ZnO and LiNbO3. We show that, using around 10 DBRs on top and below the optical cavity layer, POMCs based on ZnO/SiO2 and LiNbO3/SiO2 could, in principle, have Q-factors exceeding 104. The strong light confinement in the cavity allows us to the observe effects related to the strong photon-phonon coupling induced by the SAW. In particular, we show how the presence of SAWs leads to the formation of acoustically induced dynamic optical superlattices, which are characterized by the folding of photon dispersion in the cavity and the appearance of "mini" Brillouin zones. Our results are in very good agreement with experimental results reported in literature. They open the possibility of characterization of acoustically induced modulation in arbitrary layered systems and create a very good platform for interpretation of experimental results / Mestrado / Física / Mestre em Física / 2013/118635-2 / 2012/11382-9 / CAPES / FAPESP

En combinant des techniques de microscopie et de spectroscopie, il est possible de réaliser des images résolues spectralement. Ces images apportent des réponses à de nombreux problèmes en chimie, biologie, et médecine. La diffusion Raman cohérente (CRS) s'est révélée capable de surpasser la diffusion Raman spontanée dans l'analyse chimique d'échantillons, en offrant une meilleure résolution spatiale et un temps d'acquisition plus faible. La vitesse d'acquisition de l'information spectrale demeure toutefois un facteur limitant en imagerie CRS, et de nombreuses recherches se concentrent sur le développement de nouvelles méthodes d'acquisition. Le présent travail s'inscrit dans cette démarche. En combinant la diffusion Raman stimulée (une branche de la CRS), la focalisation spectrale d'impulsions optiques, ainsi qu'une ligne à délai acousto-optique, nous réalisons les premières mesures à de telles vitesses d'acquisition. Le cadre théorique, technologique, ainsi que l’ingénierie nécessaire pour parvenir à ce résultat sont détaillés. Cette technique d'acquisition rapide est illustrée par le suivi de réaction chimique, le contrôle qualité pharmaceutique, en biologie, et en histologie / Combining microscopy and spectroscopy, one can achieve spectrally resolved imaging, and provide a solution to various chemical, biological, or medical challenges. Coherent Raman scattering (CRS) has proven extremely valuable in providing chemical information, with a higher resolution and shorter acquisition time than spontaneous Raman scattering. The acquisition rate of the spectral information from a sample remains the limiting factor of CRS imaging, and several experimental schemes are being investigated to push the technology toward higher imaging frame rates. This work develops one such scheme. Combining stimulated Raman scattering (a CRS technique), spectral focusing with chirped pulses, and a fast acousto-optic delay line, we achieved unprecedented spectral acquisition rates. The theoretical, technological, and engineering frameworks enabling such acquisition are described in details. The application to pharmaceutical quality control, time resolved chemical transformations, biology, and histology are demonstrated

No description available.

Ces travaux de thèse visent à proposer un nouveau type de modulateur acousto-optique intégré exploitantdes ondes élastiques guidées à la surface du niobate de lithium. Ce matériau piézoélectrique permet en effet deréaliser des guides d’ondes optiques intégrés ainsi que des transducteurs à ondes élastiques efficaces. La modulationacousto-optique y reste cependant classiquement limitée par le recouvrement partiel des deux types d’ondes. J’aicherché à développer un nouveau type de guide d’ondes élastiques de surface exploitant les résonances d’épaisseurd’électrodes épaisses et permettant une meilleure exploitation de la conversion d’énergie électrique en énergieélastique dans les dispositifs intégrés.Dans un premier temps, j’ai développé un moyen de confiner l’énergie acoustique en surface afin de l’utiliserplus efficacement. Je me suis tourné vers la réalisation de transducteurs à peignes interdigités pour les ondes acoustiquesde surface permettant de confiner l’énergie qu’ils génèrent dans des électrodes à haut facteur de forme. Lacaractérisation de ces dispositifs a permis de démontrer un fort confinement de l’énergie mécanique, concomitantd’une absence de diffraction à la surface du matériau. Ces dispositifs acoustiques permettent ainsi un guidage del’énergie acoustique dans les trois dimensions de l’espace avec une largeur transverse aussi petite que la longueurd’onde.Dans un second temps, j’ai réalisé des modulateurs acousto-optiques utilisant les transducteurs précédents. Cesmodulateurs sont fondés sur un interféromètre de Mach-Zehnder dont un bras est soumis à l’interaction acoustooptique.Les expériences réalisées ont permis de montrer une modulation de l’onde optique aux fréquences de résonancedes transducteurs à haut facteur de forme. La transmission spectrale de ces interféromètres est par ailleurscannelée en raison d’une légère asymétrie des bras de l’interféromètre. Nous avons observé, à fréquence nulle, unfort décalage en longueur d’onde du spectre cannelé d’environ 20 nm. Ce décalage reste encore inexpliqué. / This thesis intended to propose a new kind of integrated acousto-optical modulator exploiting guided elasticwaves on the surface of a lithium niobate substrate. This piezoelectric material makes it possible to integrate opticalwaveguides as well as efficient elastic waves transducers. Classically, the acousto-optical modulation remainslimited by the partial overlap of the two kind of waves. I have sought to develop a new kind of surface elasticwaveguide exploiting the thickness resonances of thick electrodes allowing a better exploitation of electric energyto elastic energy conversion in integrated devices.First, I have developed a way to confine the acoustic energy at the surface to use it more efficiently. I turnedtowards the realization of interdigitated transducers for surface acoustic waves allowing to confine the generatedenergy in the high aspect ratio electrodes. The characterization of such devices allowed to demonstrate a strongconfinement of the mechanical energy at the surface of the material. These acoustic devices allowed for diffractionlessguiding of the acoustic energy in the three dimensions of space over a transverse width as small as thewavelength.The second part of this thesis was dedicated to the realization of acousto-optical modulators using the previoustransducers. These modulators are based on a Mach-Zehnder interferometer including one arm subjectd to theacousto-optical intercation. Due to a slight asymmetry of the interferometer arms, the spectrale transmission with awhite light source gives a channeled spectrum. Experiments have shown an optical wave modulation at resonancesfrequencies of the high aspect ratio transducers. We have observed, at zero frequency, a strong wavelength shift ofchanneled spectrum of about 20 nm. This shift remains unexplained.

Large area flat displays are nowadays considered being a commodity. After the era of bulky CRT TV technology, LCD and OLED have taken over as the most prevalent technologies for high quality image display devices. An important factor underlying the success of these technologies has been the development of high performance photomask writers in combination with a precise photomask process. Photomask manufacturing can be regarded as an art, highly dependent on qualified and skilled workers in a few companies located in Asia. The manufacturing yield in the photomask process depends to a great extent on several steps of measurements and inspections. Metrology, which is the focus of this thesis, is the science of measurement and is a prerequisite for maintaining high quality in all manufacturing processes. The details and challenges of performing critical measurements over large area photomasks of square meter sizes will be discussed. In particular the development of methods and algorithms related to the metrology system MMS15000, the world standard for large area photomask metrology today, will be presented. The most important quality of a metrology system is repeatability. Achieving good repeatability requires a stable environment, carefully selected materials, sophisticated mechanical solutions, precise optics and capable software. Attributes of the air including humidity, CO2 level, pressure and turbulence are other factors that can impact repeatability and accuracy if not handled properly. Besides the former qualities, there is also the behavior of the photomask itself that needs to be carefully handled in order to achieve a good correspondence to the Cartesian coordinate system. An uncertainty specification below 100 nm (3σ) over an area measured in square meters cannot be fulfilled unless special care is taken to compensate for gravity-induced errors from the photomask itself when it is resting on the metrology tool stage. Calibration is therefore a considerable challenge over these large areas. A novel method for self-calibration will be presented and discussed in the thesis. This is a general method that has proven to be highly robust even in cases when the self-calibration problem is close to being underdetermined. A random sampling method based on massive averaging in the time domain will be presented as the solution for achieving precise spatial measurements of the photomask patterns. This method has been used for detection of the position of chrome or glass edges on the photomask with a repeatability of 1.5 nm (3σ), using a measurement time of 250 ms. The method has also been used for verification of large area measurement repeatability of approximately 10 nm (3σ) when measuring several hundred measurement marks covering an area of 0.8 x 0.8 m2. The measurement of linewidths, referred to in the photomask industry as critical dimension (CD) measurements, is another important task for the MMS15000 system. A threshold-based inverse convolution method will be presented that enhances resolution down to 0.5 µm without requiring a change to the numerical aperture of the system. As already mentioned, metrology is very important for maintaining high quality in a manufacturing environment. In the mask manufacturing industry in particular, the cost of poor quality (CoPQ) is extremely high. Besides the high materials cost, there are also the stringent requirements placed on CD and mask overlay, along with the need for zero defects that make the photomask industry unique. This topic is discussed further, and is shown to be a strong motivation for the development of the ultra-precision metrology built into the MMS15000 system. / <p>QC 20130515</p>