The full dielectric tensor of monoclinic Ga2O3 (β-phase) was determined by generalized spectroscopic ellipsometry in the spectral range from 1.0 eV up to 8.5 eV and temperatures in the range from 10K up to 300K. By using the oriented dipole approach, the energies and broadenings of the excitonic transitions are determined as a function of the temperature, and the exciton-phonon coupling properties are deduced.

La concentration des espèces chimiques comme H₂O, CO₂, CO, K, HCl ainsi que les grandeurs thermodynamiques comme la pression et la température sont des paramètres clés pour comprendre les réactions de combustion. Ces données permettent de mieux caractériser la combustion dans les foyers aéronautiques et aussi d’affiner les simulations numériques qui permettent d’aider à la conception de moteurs. L’objectif est d’améliorer leur efficacité avec un meilleur rendement et une diminution du rejet de gaz polluants. L’objectif de la thèse est de développer une méthode de caractérisation optique non-intrusive permettant d’obtenir des cartographies de concentrations d’espèces chimiques, de température et de pression dans ces flammes. Cette méthode consiste à acquérir des spectres d’absorption à plusieurs positions et angles dans l’écoulement réactif. L’inversion spectral de ces données permettra de remonter quantitativement aux concentrations chimiques, à la pression et à la température. Dans la thèse, nous avons choisi de combiner cette inversion spectrale à un algorithme de tomographie permettant d’améliorer la résolution spatiale. La méthode développée est appelée Tunable Diode Laser Absorption Tomography (TDLAT). Deux axes de recherches ont été poursuivis au cours de la thèse. Le premier a consisté à développer plusieurs spectromètres d’absorptions associés à un système mécanique de balayage spatial de la flamme. Dans un second temps, nous avons cherché à développer un algorithme de tomographie non-linéaire permettant d’exploiter les séries de spectres d’absorption pour obtenir la résolution spatiale. Les principaux résultats obtenus en simulation ont permis d’optimiser l’algorithme et aussi d’adapter son fonctionnement aux configurations de mesures représentatives des bancs de combustion. Les principaux résultats de mesures ont été enregistrés dans une flamme de laboratoire et sur un banc de combustion de propergol solide. / Chemical species densities like H₂O, CO₂, CO, K, HCl and thermodynamic data like pressure and temperature are keys parameters to understand combustion. Measurements of these parameters are great help to validate or complement numerical simulations aiming at improving engine design and efficiency. The current thesis presents the development of an optical characterization method leading to two dimensional maps of chemical densities, pressure and temperature in combustion flames. This method consists to acquire absorption spectra at different positions and angles around the reactive flow. The spectral inversion of these data can be used to recover quantitatively chemical densities, pressure and temperature. In this thesis, we have chosen to combine this spectral inversion with a tomographic algorithm in order to obtain results with improved spatial resolution. The developed method is called Tunable Diode Laser Absorption Tomography (TDLAT).Two research directions have been followed during the thesis. The first consisted to develop several absorption spectrometers associated with a mechanical scanning device of the flame. In a second time, we have searched to develop a non-linear tomographic algorithm in order to process absorption spectra series in order to obtain spatial resolution. The main results obtained in simulations have led to an optimization of the tomographic algorithm in order to adapt its functioning to measurements configurations characteristics of combustion benches. The main measurements results have been acquired in a laboratory flame and in a solid propellant combustion bench.

Ce travail de thèse porte sur l’étude de deux éléments au cœur d’un système de nanopositionnement et de micromanipulation : a) un capteur interférométrique intégré sur puce ; ses caractéristiques, particularités et potentiels sont étudiés en détails ; b) un élément utilisable en capteur et actionneur : un polymère électro-actif à flexions.L'interféromètre PicoMove est le résultat de l'étroite collaboration entre LISV et l’entreprise TeemPhotonics. Cet interféromètre, qui fonctionne dans le domaine de l'infrarouge moyen (1,55 µm) est basé sur la technologie des guides d'ondes optique lui offrant une plus grande robustesse vis-à-vis de l'environnement extérieur. son architecture est basée sur une structure Michelson-Young modifiée. Des expérimentations ont été mises en œuvre pour caractériser ses performances. Il a été démontré une résolution sub-nanométrique et un très faible niveau de bruit. Une densité spectrale de puissance de 100 fm/√Hz a été atteinte en condition statique.En outre, sa robustesse aux conditions environnementales est démontrée, et ses sources d’erreurs et spécificités métrologiques sont discutées au travers d’une application sur un étage de nanopositionnement, fonctionnant avec un moteur à bobine mobile et un guidage flexible.Le second point de cette thèse concerne l’étude des propriétés électro-mécaniques d'un polymère électro-actif ionique (IEAP) en configuration poutre encastrée. Il est capable de fonctionner en mode actionneur et en mode capteur. Pour la partie actionneur, sa raideur et fréquence propre sont déterminées. Pour la partie capteur, sa bande passante, sa résolution et sa fonction de transfert sont étudiées expérimentalement.Les capacités micrométriques de ce polymère en mode actionneur et en mode capteur sont démontrées et discutées. / This work concerns the study of two elements of a system of nanopositioning and micromanipulation: a) integrated on-chip interferometric sensor; its characteristics, peculiarities and potential are studied in detail; b) an element usable in sensor and actuator mode: an electro-active flexural polymer.The PicoMove interferometer is the result of the collaboration between LISV and the company TeemPhotonics. This interferometer, which operates in the mid-infrared range (1.55 μm), is based on optical guide technology that gives a high degree of robustness to the external environment. Its architecture is based on a modified Michelson-Young structure. Experiments have been implemented to characterize its performance. It has been demonstrated nanometric resolution and very low noise level. A spectral power density of 100 fm/√Hz was reached under static conditions.In addition, its robustness to the environmental conditions is demonstrated, and the metrological specificities are discussed with details about the specific error sources. It is applied to a nanopositioning stage using mobile coil and flexible guidance.The second point of this PhD work concerns the study of electromechanical properties of an ionic electroactive polymer (IEAP) in a flexible cantilever configuration. It is able to operate in actuator mode and in sensor mode. For the actuator part, its stiffness and its natural frequency are studied. For the sensor part, its bandwidth, resolution and transfer function are experimentally studied.The micrometric capabilities of this polymer in actuator and sensor mode are demonstrated and discussed.

Detta kandidatexamensarbete behandlar vågkraftverket “NoviOcean” och syftar till att skapa en rekommendation för de mätstorheter som bör övervakas, vilka mätprinciper som är lämpliga, samt eventuellt var sensorerna för dessa bör placeras. Först gjordes en informationssökning, för att förbättra förståelsen för hur vågkraftverket fungerar och vilka komponenter som ingår i konstruktionen. Detta gjordes dels genom att söka igenom företagets officiella dokument och dels med en genomgång med en tekniskt ansvarig från företaget, med en prototyp i mindre skala. Utöver detta undersöktes de förhållanden vågkraftverket kommer användas i, även här genom möten med ansvariga från företaget, för att öka förståelsen för vad produkten kommer utsättas för. När en komplett bild av vågkraftverkets funktion hade genererats påbörjades arbetet med att föreslå mätstorheter. Det första steget var att dela upp produkten i delsystem, för att strukturera upp arbetet. Detta gjorde det möjligt att sedan för respektive delsystem föreslå mätstorheter, som kan ge information om systemets prestanda, hälsa och miljön runtomkring. När de önskade mätstorheterna etablerats gjordes sedan ytterligare en informationssökning, för att undersöka vilka mätprinciper som ansågs vara lämpliga för produkten. Av dessa valdes en eller fler sensortyper ut, om det ansågs finnas mer än en lämplig lösning. Vissa sensorer kunde även placeras ut på enheten, då tillräckligt med information om det relevanta delsystemet ansågs finnas.' I stort anses den slutgiltiga rekommendationen av mätstorheter och mätprinciper uppfylla de krav som ställdes från företaget. En lista för respektive delsystem detaljerar de storheter och principer som anses lämpliga, med bilder och skisser för placering om detta bedömdes genomförbart. I bilagorna återfinns även mer specifika förslag för vidare arbete, för några av delsystemen. / This bachelor thesis report focuses on the Wave Energy Converter (WEC) “NoviOcean” and aims to recommend the physical quantities that should be measured aboard the unit, as well as the appropriate measuring principle for each quantity. An approximate position of each sensor was also recommended, if deemed possible. The first step was to complete a literature study, to form a better understanding of the product and its components. This was done in part by going through the company’s official documents and in part by interviewing the head of mechatronics, with a walk-through of a miniature prototype. Additional meetings with the company were also held, to better understand how and where the product is intended to be used and what conditions it will be exposed to. When the product and its function had been sufficiently understood, the work of suggesting measuring quantities began. The entire system was first divided into smaller sub-systems, to organize and simplify the process. A list of recommended quantities was then generated, that could provide information about the system’s performance, health and surroundings. Once finished, an additional literature study was performed, to understand what measuring principles would be appropriate for each quantity. The most suitable principle was then chosen from this list, unless there was more than one solution, in which case all options were included. Sensor placement could also be determined in some cases, provided that the relevant sub-system was sufficiently well defined. In conclusion, the final recommendation for measured quantities and measuring principles fulfills the demands placed by the commissioner of this report. A list of quantities and measuring principles was generated for each sub-system, with images and sketches detailing sensor placement, if applicable. For some systems, more specific sensor recommendations could be made, the results of which can be found in the appendix.

Detta examensarbete har utförts på uppdrag av DeLaval, ett företag inom mjölkningsindustrin. Projektets huvudmålsättning var att automatisera kalibreringen av DeLavals mjölkningsrobot VMS v300. Kalibreringen av mjölkmätarna, som mäter mängden mjölk under mjölkning, måste ske manuellt. Dagens kalibreringsprocess är ICAR-godkänd vilket innebär att ICAR sätter upp riktlinjer för hur noggrann mätningen ska vara för att vara godkänd. Arbetet har utförts på distans vilket innebär att det endast finns teoretiska beräkningar, enklare skisser, och teoretiska modeller i rapporten.  Arbetet inleds med en faktagenomgång, där processen kring hur kalibreringen utförs förtydligas. Vidare förklaras även hur mycket mjölk som fås av en ko under en mjölkning, vilken mjölkmätare som används, kalibreringsparametrar, lösningsförslag, och hur den automatiserade kalibreringen av en AMR (Automatic Milking Rotary) fungerar. Med hjälp av matematiska beräkningar och simuleringar utvärderas lösningsförslagen. Slutsatsen är att nivåmätaren, som nu finns placerad och kan användas i VMS:en, inte når de krav som ställs på kalibreringen. Istället kan en ultraljudssensor ersätta den nuvarande nivåmätaren och erhålla en godkänd kalibreringsprocess. Detta innebär att kalibreringsprocessen kan automatiseras. / This report is a thesis commissioned by the dairy industry company DeLaval. The main objective of theproject was to automate DeLaval's calibration of its milking robot VMS v300. At present, DeLavalneeds to manually calibrate the milk meters, that measure the amount of milk during milking, to getan accurately measured amount of milk. Today's calibration process is ICAR-approved, which meansthat ICAR sets guidelines for how accurate the measurement must be for approval. The work has been carried out remotely, which means that there are only theoretical calculations,simpler sketches, and theoretical models in the report. The work begins with a factual review, which clarifies the process of how the calibration is performed.Furthermore, it is also explained how much milk is obtained by a cow during milking, which milkmeter is used, calibration parameters, solution suggestions, and how the automated calibration of anAutomatic Milking Rotary (AMR) works. By means of mathematical calculations and simulations, a model is set up to evaluate the solutionproposals, which resulted in a feasible model. The conclusion for the work is that the level meter,which is now located and can be used in the VMS, does not meet the requirements set for thecalibration. Instead, an ultrasonic sensor can replace the current level meter and obtain an approvedcalibration process. This means that the calibration process can be automated.

This thesis project was undertaken with the intent to discover the source of a known but hitherto unexplained error in the calibration of the wings for a haploscope used in depth perception studies. The angles of the haploscope wings are used to control the vergence angle of the virtual images projected into each eye. This accounts for a strong depth cue used in AR and depth perception studies. Two experiments were devised to both display and attempt to characterize the error between the theoretical wing angles needed to cause a user's vision to verge at some focal depth and the actual wing angles that caused vergence. The investigation revealed a near-constant offset between the theoretical and actual angles needed. This suggests that the error may not stem from the haploscope alignment itself, but from how the center of the user's eye is currently modelled.

Wavefront sensing is a fundamental problem in applied optics. Wavefront sensors that work in a deterministic manner are of particular interest. Initialized with a unified theory for classical wavefront sensors, this dissertation discusses relevant properties of wavefront sensor designs. Based on which, a new wavefront sensor, termed Coded Wavefront Sensor, is proposed to leverage the advantages of the analysis, especially the lateral wavefront resolution. A prototype was built to demonstrate this new wavefront sensor. Given that, two specific applications are demonstrated: megapixel adaptive optics and simultaneous intensity and phase imaging. Combined with a spatial light modulator, a hardware deconvolution approach is demonstrated for computational cameras via a high resolution adaptive optics system. By simply switching the normal image sensor with the proposed one, as well as slight change of illumination, a bright field microscope can be configured to a simultaneous intensity and phase microscope. These show the broad application range of the proposed computational wavefront sensing approach. Lastly, this dissertation proposes the idea of differentiable optics for wavefront engineering and lens metrology. By making use of automatic differentiation, a physically-correct differentiable ray tracing engine is built, with its potentials being illustrated via several challenging applications in optical design and metrology.

[pt] A previsão da energia elétrica produzida com energia solar pode ser usada para monitorar em tempo real seu desempenho, permitindo a identificação de problemas operacionais ou sua degradação, assim como a previsão da produção de energia elétrica a curto e médio prazo, permitindo otimizar o uso da rede. Normalmente, a previsão de dados climáticos ao longo do dia serve para ajudar a estabilidade da rede elétrica. Já a previsão de dados para um dia ou mais à frente serve para apoiar a participação de mercado. Esta pesquisa tem como objetivo geral propor um modelo de previsão a curto prazo da irradiação solar a partir de correlações de condições climáticas, visando diminuir as incertezas de previsão da mesma, que pode ser usado para prever a geração fotovoltaica. O modelo de previsão proposto se baseia em identificar os dias de céu limpo, caracterizados pela ausência de nuvens, e dias totalmente nublados. Para sua identificação, foram utilizadas formulações já consagradas na literatura. Para os demais dias, a previsão da irradiação é feita a partir de regressões e correlações entre temperatura ambiente e transmitância atmosférica. A escolha do modelo de céu limpo é um fator preponderante para a previsão, podendo aumentar significativamente sua confiabilidade. Diversos modelos de previsão foram avaliados e combinados para uma melhor previsão da irradiação solar média incidente na superfície terrestre. A partir de dados de irradiação solar e temperatura, medidos a cada minuto por quatro anos na cidade de Miranda do Norte, Maranhão, foi possível analisar, interpretar e propor um modelo para a previsão da irradiação solar média com incertezas de 22-24 porcento, 14-16 porcento, 13-15 porcento e 12-13 porcento, a nível de confiabilidade de 95,45 porcento, respectivamente para horizontes de 1, 3, 5 e 7 dias à frente. A utilização do método dos mínimos quadrados para previsão apresenta incertezas muito maiores. O modelo proposto apresenta-se eficaz para prever a irradiação solar. Sua utilização e facilidade de implementação podem ser de grande valia para a prever o planejamento diário e semanal da produção de usinas fotovoltaicas. Foi usado o modelo de previsão sugerido por Bindi, juntamente com três modelos de céu limpo para redução da incerteza de previsão. / [en] The prediction of the electric energy production by solar energy systems can be used as a real time monitoring of its performance, allowing the identification of operational problems or its performance degradation, as well as the short and medium term production of electric energy, thus optimizing the use of the electric network. Normally, the daylong climactic data prediction is useful for helping stabilizing the electric network. The one or more day ahead prediction of electric energy is a useful tool for planning the energy supply to the market. The main goal of this research is to propose a short-term prediction model for the solar irradiation by means of weather condition correlations, in doing so, we expect to lower the uncertainties of the solar irradiation forecast, for which can be used to forecast photovoltaic energy. The proposed prediction model uses literature available correlations for clear sky (no clouds) and overcast days, to predict the solar irradiation in other days, through the use the ambient temperature and atmospheric transmission literature available correlations. Several prediction models were used and combined for 1, 3, 5 and 7 days ahead prediction of the available average solar energy in that time interval . It was concluded that the clear sky model plays an important role in the prediction reliability. Experimental data taken every minute for almost four years in the city of Miranda do Norte in the state of Maranhão, Brazil, were used to verify and propose a model to better predict the available solar energy irradiation, to within 22-24 percent, 14-16 percent, 13-15 percent and 12-13 percent uncertainty (95,45 percent confidence level), respectively for 1, 3, 5 and 7 days ahead of the available solar irradiation in the time interval. The least square model was also analyzed and it was shown to predict the solar irradiation with much higher uncertainties. As a result, the proposed model can be easily implemented for predictions in other places and can be very useful for predicting and planning the daily and weekly output of photovoltaic plants. In this dissertation the prediction model suggested by Bindi was utilized, together with three clear sky models to reduce the prediction uncertainty.

The construction and characterization of ultra-low noise semiconductor-based mode-locked lasers as frequency comb sources with multi-gigahertz combline-to-combline spacing is studied in this dissertation. Several different systems were built and characterized. The first of these systems includes a novel mode-locking mechanism based on phase modulation and periodic spectral filtering. This mode-locked laser design uses the same intra-cavity elements for both mode-locking and frequency stabilization to an intra-cavity, 1,000 Finesse, Fabry-Pérot Etalon (FPE). On a separate effort, a mode-locked laser based on a Slab-Coupled Optical Waveguide Amplifier (SCOWA) was built. This system generates a pulse-train with residual timing jitter of

Long wave infrared (LWIR) optics that transmit in the 8 to 14 m wavelength range and, additionally, can withstand severe physical and thermal stresses are needed for advanced remote sensing, guidance and communication-based applications. However, most non-oxide transparent LWIR optics do not have the wider transmission range, nor the hardness and resistance to thermal shock needed for extreme environments. Because of these limitations, research is circling back to a promising material, calcium lanthanum sulfide (CLS), that could meet LWIR needs for extreme environments. In this thesis, we will demonstrate the abilities of x-ray photoelectron spectroscopy (XPS) as a technique for characterizing CLS powders and ceramics for elemental analysis, valence state and stoichiometry evaluation. Three preliminary studies were conducted - a binary metal sulfide evaluation of lanthanum sulfide (La2S3) and calcium sulfide (CaS), and a calibration curve of mixtures of the two binary metal sulfide powders from a known concentration matrix. Based on these results, a methodology was developed to evaluate CLS powder and ceramics via XPS. We showcase the power of XPS to reliably determine CLS stoichiometry, identify impurities and defects as related to the presence of carbon and oxygen during processing, and predict the bonding environment of sulfur which can lead to better quality CLS ceramics. This thesis demonstrates the use of XPS as a potential characterization tool in CLS to identify contaminants, determine if stoichiometry is met, and identify the bonding environments to assist in processing improvements for producing higher-quality ceramics.