Dissertations / Theses on the topic 'Laser Line Detection'

Infrared absorption spectra can provide analytically useful information on a large variety of compounds, ranging from small ions to large biological molecules. In fact, all analytes that possess a dipole moment that changes during vibration are infrared-active. The infrared (IR) spectrum can be subdivided into far-, mid- and near- regions. The focus of attention in this thesis is the mid-IR region, in which the fundamental vibrations of most organic compounds are located, thus providing scope for positive structural identification. However, while such near-ubiquitous signals can be very useful for monitoring simple molecules in simple systems, they can be increasingly disadvantageous as the number of analytes and/or the complexity of the sample matrix increases. Thus, hyphenation to a separation system prior to detection is desirable. Paper I appended to this thesis presents (for the first time) the on-line hyphenation between Fourier transform infrared spectroscopy, FTIR, and capillary zone electrophoresis, CZE. CZE is a highly efficient separation technique that separates ionic analytes with respect to their charge-to-size ratio. It is most commonly performed in aqueous buffers in fused silica capillaries. Since these capillaries absorb virtually all infrared light an IR-transparent flow cell had to be developed. In further studies (Paper II) the applicability of CZE is expanded to include neutral analytes by the addition of micelles to the buffer, and micellar electrokinetic chromatography, MEKC, was successfully hyphenated to FTIR for the first time. Paper III describes an application of the on-line CZE-FTIR technique in which non-UV-absorbing analytes in a complex matrix were separated, identified and quantified in one run.

Measuring aqueous solutions in the mid-IR region is not straightforward since water absorbs intensely in this region, sometimes completely, leaving no transmitted, detectable light. For this reason, quantum cascade lasers are interesting. These lasers represent a new type of mid-IR semiconducting lasers with high output power due to their ingenious design. The laser action lies within one conduction band (intersubband) and can be tailored to emit light in the entire mid-IR region using the same semiconducting material. To investigate their potential to increase the optical path length in aqueous solutions, these lasers were used with an aqueous flow system (Paper IV), and the experience gained in these experiments enabled hyphenation of such lasers to a CZE system (Paper V).

In this study, a calibration setup for laser beam positioning systems used in visual inspection applications in industry is designed and manufactured. The laser positioning systems generate movable parallel laser lines on the projection surface. There are several translational and angular error sources affecting the positioning accuracy of the laser lines on the projection surface. Especially, since the laser line positioning error caused by angular error sources increases with the distance between the laser system and the projection surface, angular parameters of the laser sources should be measured and adjusted precisely. The calibration setup developed in this study detects the laser line positions at two different projection distances by means of laser sensing cameras which are positioned precisely along the laser lines and laser positioning axis which is perpendicular to these lines. Cameras detect the positions of the laser lines which are directed to the camera sensors with micrometer repeatability by means of some special imaging algorithms. The precise positioning of the cameras requires a special camera positioning system. For this reason, the disturbances like temperature changes and vibration should be minimized. In order to provide a suitable environment for the calibration system, special tests are conducted and a special calibration room is constituted. Construction inside the room is also made by considering the required ambient parameters. Finally, several verification tests of the calibration system are conducted.

Cette thèse s’inscrit dans le cadre d’une convention industrielle de formation par la recherche (CIFRE) entre le laboratoire Hubert Curien et l’entreprise Pattyn Bakery Division. L’objectif de ces travaux est le développement d’un système de détection de trait laser sur FPGA (Field Programmable Gate Array) qui soit plus performant que système actuel de l’entreprise. Dans l’industrie, les concepteurs de systèmes de vision doivent pouvoir créer et modifier facilement leurs systèmes afin de pouvoir les adapter aux besoins de leurs clients et aux évolutions technologiques. Ainsi les opérateurs développés doivent être génériques afin de permettre aux concepteurs de modifier le système de vision sans nécessairement avoir de compétences matérielles. Les concepteurs doivent également pouvoir être en mesure d’estimer quelles seront les ressources utilisées par l’opérateur en cas modifications du système : paramètres de l’application, capteur, famille de FPGA... Dans ce manuscrit, les principaux algorithmes de détection de trait laser ainsi que leurs propriétés ont été étudiés. Un opérateur de détection de trait laser a été choisi et développé. L’implantation de cet opérateur sur une caméra-FPGA du marché a permis d’obtenir un premier prototype fonctionnel. Les performances temporelles de ce nouveau système sont quatre fois supérieures à celles du système actuellement utilisé par l’entreprise. Le nouveau système est capable de traiter jusqu’à 2500 images par seconde. Enfin, les modèles de la consommation des ressources permettent de dimensionner une architecture à partir d’un ensemble de paramètres prédéfinis de manière rapide et sans faire de synthèses. Le paramètre auquel les concepteurs doivent prêter le plus d’attention est le niveau de parallélisme des données. Ce paramètre permet d’exploiter les capacités de parallélisme du FPGA en consommant plus de ressources. Cependant, les ressources du FPGA sont limitées et augmenter le niveau de parallélisme peut induire la nécessité de changer de FPGA. Le système et les données fournies permettront à l’entreprise d’adapter le système de vision selon les besoins futurs des clients en les guidant vers le choix du matériel
This thesis is part of an industrial research training agreement (CIFRE) between the Hubert Curien laboratory and the company Pattyn Bakery Division. The goal of this work is the development of an FPGA laser line detection system that is more efficient than the current system of the company. In the industry, vision system designers need to be able to easily create and modify their systems in order to adapt them to their customers’ needs and technological developments. Thus developed operators must be generic to allow designers to change the vision system without necessarily having material skills. Designers must also be able to estimate what resources will be used by the operator in case of system changes : application parameters, sensor, family of FPGAs ... In this manuscript, the main laser line detection algorithms and their properties have been studied. A laser line detection operator was chosen and developed. The implementation of this operator on an FPGA-camera from market has resulted in a first functional prototype. The time performance of this new system is four times that of the system currently used by the company. The new system is able to process up to 2500 frames per second. Finally, resource consumption models makes it possible to size an architecture from a set of predefined parameters quickly and without synthesizing. The parameter to which designers must pay the most attention is the level of parallelism of the data. This parameter makes it possible to exploit the parallelism capabilities of the FPGA by consuming more resources. However, the resources of the FPGA are limited and increasing the level of parallelism can induce the need to change the family of FPGAs. The system and the data provided will enable the company to adapt the vision system to the future needs of customers by guiding the choice of equipment

Thesis (Ph. D.) -- University of Maryland, College Park, 2003.
Thesis research directed by: Biological Resources Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

The objective of this thesis work is to increase the functionality of optical fibers for possible applications in life-sciences. Optical fibers are a promising technology for use in biology and medicine. They are low-costwaveguides, flexible and have a small cross-section. They can guide high-power light with low loss in a micrometer core-size. These features make fibers attractive for minimally-invasive,in-vivostudies. The backwards guidance of the optical signal allows for real-time monitoring of the distance to the scattering targets and to study the environment through Raman scattering and fluorescence excitation. The longitudinal holes introduced in the fibers can be used,for instance,for delivery of medicine to a specific regionof a body. They could even be used for the extractionof species considered interesting for further analysis, for example, studyingcells that may be cancer-related. This thesis deals with four main topics. First, a demonstration is presented of the combination of high-power light guidance for ablation, low-power light reflectometry for positioning, and for liquid retrieval in a single fiber. It was found that in order to exploit the microfluidic possibilities available in optical fibers with holes, one needs to be able to combine fluids and light in a fiber without hindering the low-loss light guidance and the fluid flow. Secondly, one should also be able to couple light into the liquids and backout again. This is the subject of another paper in the present thesis. It was also observed that laser excitation through a fiber for the collection of a low-intensity fluorescence signal was often affected by the luminescence noise createdby the primary-coating of the fiber. This problem makes it difficult to measure low light-levels, for example, from single-cells. Athirdpaper in this thesis then describes a novel approach to reduce the luminescence from the polymer coating of the fiber, with the use of a nanometer-thick carbon layer on the cladding surface. Finally, exploiting some of the results described earlier, an optical fiber with longitudinal holes is used for the excitation, identification and for the collection of particles considered being of interest. The excitation light is guided in the fiber, the identification is performed by choosing the fluorescent particles with the appropriate wavelength, and, when a particle of interest is sufficiently near the fiber-tip, the suction system is activated for collection of the particle with good specificity. It is believed that the work described in this thesis could open the doors for applications in life-sciences and the future use of optical fibers for in-vivo studies.

QC 20140516

Les attaques bioterroristes sont devenues plus fréquentes ces dernières années et le large éventail d’agents bioterroristes en fait un problème important à résoudre. La ricine appartient à la famille des protéines inactivant les ribosomes (RIP). Les RIP sont des toxines biologiques, solubles dans l’eau, qui peuvent être facilement extraites de plantes (ricine de Ricinus communis et abrine d’Abrus precatorius) ou de bactéries (toxine de Shiga). La ricine est composée de deux chaînes: la chaîne A de la ricine, une N-glycosidase induisant la toxicité par élimination de l’adénine (action de dépurination) de l’ARNr 28S des sous-unités ribosomales 60S, inhibant la synthèse protéique, et la chaîne B, une lectine qui se lie aux fragments de sucre spécifiques sur la membrane extracellulaire, assurant l'absorption de la toxine. Comme ils inhibent la synthèse des protéines, en fonction de la voie d'absorption et de la dose reçue, la mort peut survenir. En l'absence de contre-mesures efficaces, les méthodes de détection de ces toxines doivent être rapides, fiables, sélectives et sans aucune ambiguïté. Les méthodes actuelles qui sont principalement basées sur des méthodes comme le SERS, l’ELISA, la Colorimétrie et la SPR ne répondent pas à toutes ces exigences. Même si la spectrométrie de masse a été utilisée pour la détection de la ricine, elle ne peut pas être réalisée sans une longue et fastidieuse préparation d'échantillon. Dans ce travail, nous avons montré comment les matériaux à base de carbone (nanomurs de carbone) pourraient être appliqués comme matériaux nanostructurés pour la détection spécifique, rapide et simple de la ricine par désorption/ionisation laser de surface pour la détection par spectrométrie de masse (SALDI-MS). Tout d'abord, l'adéquation des nanoparticules de carbone en tant que bonne surface SALDI a été initialement étudiée pour des biomolécules plus petites. En ce qui concerne les protéines, la littérature a montré qu'elles sont difficiles à ioniser et à détecter avec la méthode SALD-MS, en raison de leur grand poids moléculaire. La capacité des CNWs à désorber et à ioniser les protéines a nécessité de nombreuses étapes d’optimisation. Pour ce faire, le cytochrome C a été utilisé comme protéine modèle. Enfin, des nanomurs de carbone alignés verticalement ont ensuite été modifiés à l'aide de sucres à lectine spécifiques (galactosamine), pour la détection spécifique de la chaîne B de la ricine dans des échantillons réels, tels que des boissons sans alcool et du sérum sanguin. Nous avons obtenu une limite de détection (80 ng/0.5 μL) soit trois fois inférieure à la dose létale médiane la plus faible (DL50 = 10 μg/kg). Cette détection peut être réalisée dans les 10 min. Dans la dernière partie, des résultats préliminaires concernant la mise au point d'outils analytiques bimodaux seront présentés. Il s'agit de combinaisons telles que: SPR (résonance plasmonique de surface)-MS, SERS (Spectroscopie Raman Exaltée de Surface)-MS et EC(Électrochimie)-MS. Une attention particulière a été portée sur la SPR-MS car elle permet d’obtenir des interactions quantitatives et moléculaires en temps réel (SPR) et une identification structurelle des analytes (MS). Les méthodes de dépôt suivantes (de matériaux de type graphène) sont avérées appropriées pour la détection des protéines: la méthode de surfactant à bulle d'oxyde de graphène, le transfert par voie humide de graphène CVD et le dépôt électrophorétique de graphène.Cette thèse décrit pour la première fois le développement d'un capteur de type SALDI-MS, capable de détecter la ricine à une dose inférieure à la dose mortelle chez l'homme et d'apporter ainsi une contribution importante à la lutte contre d'éventuelles attaques terroristes. L'étude systématique de différents paramètres qui influencent ce processus LDI-MS est également présenté. Les techniques bimodales présentent des alternatives intéressantes permettant de créer des outils analytiques plus puissants
Bio-terroristic attacks have become more frequent in the past years and the wide range of bio-terroristic agents makes this an important issue to overcome. Ricin is part of the ribosome-inactivating proteins (RIP). RIPs are vegetable toxins, water soluble, which can be easily extracted from plants (ricin from castor beams, abrin from rosary pea) or from bacteria (Shiga toxin). These proteins are composed of two chains: ricin A chain, a glycosidase that insures the toxicity by removal of adenine (depurination) from the RNAr 28S from the 60S ribosomal subunits, followed by the inhibition of protein synthesis, and ricin B chain, a lectin that binds to specific sugar moieties on the surface of the cells, assuring transportation the cell uptake. As they inhibit protein synthesis, depending of the administration take-up (oral, inhalation, intravenously) and the dose received, cell death also occurs. In the absence of efficient counter measurements, detection methods of these toxins have to be fast, reliable, selective and suitable, especially pre-assimilation analysis. The current methods (based on SERS, ELISA, Colorimetric, SPR and MS) do not overcome all these requirements. Even though mass spectrometry was used for ricin detection, it cannot be performed without long and tedious sample preparation. In this work, we describe how carbon-based materials (carbon nanowalls and others) can be used as nanostructured materials for specific, rapid and straightforward ricin-like proteins detection, using surface assisted laser/desorption ionization mass spectrometry (SALDI-MS). The suitability of the carbon nanowalls (CNWS) was proven initially for other smaller bio-molecules.When it comes to proteins, they are hard to ionize and detect using SALD-MS, due in part to their big molecular weight. The ability of CNWs to desorb and ionize proteins required a lot of optimization steps of the SALDI-MS method. A systematic optimization was done using a model protein, the cytochrome C. From this, we were able, for the first time, to detect Ricin B chain without the use of organic matrix. To go further in improving Ricin detection performances, carbon nanowalls were then covalently modified using specific lectin sugars (galactosamine) and the ability to detect Ricin B chain in real samples such as soft drinks and blood serum was demonstrated within10 minutes. We obtained a limit of detection (80 ng/0.5 μL) that is 3 times lower than the lowest median lethal dose (LD50 = 10 μg/kg) Multifunctional surfaces are described as perspectives for more powerful bimodal analytical tools, by combining two techniques, such as: SPR(Surface Plasmon Resonance)/SALDI-MS, SERS(Surface Enhanced Raman Spectroscopy)/SALDI-MS and EC(Electrochemistry)/SALDI-MS. Special attention was focused on SPR/SALDI-MS as it can achieve both quantitative and molecular interactions in real-time (SPR) and precise identification of the analytes (MS). Different depositions methods of graphene-like materials were studied to ensure a good surface coverage of the substrate and the followings methods were suitable for protein detection: bubble surfactant method of graphene oxide, wet transfer of CVD pristine graphene, electrophoretic deposition of graphene.In this thesis, we described the first world wide ricin-like proteins SALDI-MS sensor, which is able to detect below the lethal dose in humans and bring an important contribution to the fight against eventual terroristic attacks. The systematic study of different parameters that influence this LDI-MS process is also presented. The dual surfaces studied, in particular the SPR/MS bimodal techniques, presented reliable consistency for further approaches in creating more powerful analytical tools

In this research, a novel machine learning method is designed and applied to Mine Countermeasure Missions. Similarly to some kernel methods, the proposed approach seeks to compute a linear model from another higher dimensional feature space. However, no kernel is used and the feature mapping is explicit. Computation can be done directly in the accessible feature space. In the proposed approach, the feature projection is implemented by constructing a large hidden layer, which differs from traditional belief that Multi-Layer Perceptron is usually funnel-shaped and the hidden layer is used as feature extractor. The proposed approach is a general method that can be applied to various problems. It is able to improve the performance of the neural network based methods and the learning speed of support vector machine. The classification speed of the proposed approach is also faster than that of kernel machines on the mine countermeasure mission task.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
The morphology of extruded multiphase polymer systems is usually assessed through off-line characterization methods such as microscopy, which require much time for sample preparation and analysis of the results. This work aimed to the improvement of an optical detector to measure in real time the morphology of blends and polymeric composites in processing by extrusion, by laser light scattering at low angle (LALLS). Such equipment includes hardware and software and is based on measuring the intensity of light from a laser and is spread across and under the melt flow. The signals are collected by an array 91 of photodetectors sent to a computer, and displayed in real time on a three- dimensional plot of scattered light intensity to form a surface defined by 321 points. When analyzing the scattering profile valuable information can be determined that help to elucidate the morphology of the second phase particles. The LALLS detector was tested on bench using standard samples, which were prepared so that one of its parameters (orientation, second phase concentration, dispersed particle size or type of dispersed particle) were known. This allowed the systematic study of these samples and the detector device validation. Finally, the device was tested in real time on the extrusion process, and under different materials and operating conditions. Thus, the LALLS detector device created by the group was improved making it possible to evaluate in a practical way and in real time polymer blends in solid films and morphology of some blends and polymeric composites during extrusion.
A morfologia de sistemas poliméricos polifásicos é usualmente avaliada através de métodos de caracterização off-line, tal como a microscopia, os quais demandam muito tempo para a preparação das amostras e para a análise dos resultados. Este trabalho teve como principal objetivo o aperfeiçoamento de um detector óptico para medida em tempo real da morfologia de misturas e compostos poliméricos no processamento por extrusão, através do espalhamento de luz laser em baixo ângulo (LALLS). Tal equipamento inclui hardware e software e baseia-se na medida da intensidade da luz que provém de um laser e que é espalhada através do material fundido e sob fluxo. Os sinais são coletados por um arranjo de 91 fotodetectores, enviados a um computador, e apresentados em tempo real num gráfico tridimensional da intensidade de luz espalhada formando uma superfície definida por 321 pontos. Ao se analisar o perfil de espalhamento tem-se valiosas informações que ajudam elucidar a morfologia das partículas de segunda fase presentes. O detector de LALLS foi testado em bancada com o uso de amostras-padrão, as quais foram elaboradas de maneira que um de seus parâmetros (orientação, concentração de segunda fase, tamanho de partícula dispersa ou tipo de partícula dispersa) tivesse sido alterado de forma conhecida. Isso permitiu o estudo sistematizado dessas amostras e a validação do dispositivo detector. Por fim, o dispositivo foi testado em tempo real no processo de extrusão, sob diferentes condições materiais e de operação. Com isso, o dispositivo detector de LALLS criado pelo grupo foi aperfeiçoado possibilitando avaliar-se de forma prática e em tempo real: a morfologia de misturas poliméricas na forma de filmes sólidos e algumas misturas e compostos poliméricos durante a extrusão.

Nous reportons dans ces travaux de thèse le développement de deux spectromètres à lasers fonctionnant dans la région spectrale du moyen infrarouge (2,78 µm et 8 µm) correspondant aux deux fenêtres atmosphériques pour la détection de traces de gaz. Le premier spectromètre, basé sur la génération de différence de fréquences (DFG) vers 2,78 µm, est couplé à un spectromètre utilisant un laser à cascade quantique (QCL) vers 8 µm dans une cellule multipassages. Ce montage croisé nous a permis de déterminer pour la première fois expérimentalement les intensités de 31 raies d’absorption les plus intenses de la branche Q de la bande fondamentale ν₁ de l’isomère trans de l’acide nitreux (trans-HONO), considéré comme espèce clé pour la capacité d'oxydation atmosphérique. Nous avons exploité le spectromètre à QCL lors d’une campagne de mesures ciblée sur la surveillance continue du méthane (CH₄) pendant le mois de janvier 2013 à Dunkerque. Les observations de la variation de la concentration du CH₄ ont été analysées à l'aide des paramètres météorologiques simultanément enregistrées. Face au besoin d’identification de ses sources d’émission, nous avons développé la technique IRLS (Isotope Ratio Laser Spectrometry) pour la mesure du taux isotopique de ¹³CH₄/¹²CH₄. Les résultats préliminaires sont présentés
I report in this PhD thesis on the development of two mid-infrared laser spectrometers, based on difference-frequency generation (DFG) and quantum cascade laser (QCL), for application to trace gas monitoring. The DFG spectrometer (2.78 µm) was coupled with the QCL spectrometer (8 µm) to simultaneously measure nitrous acid (HONO) absorption spectra of the v₁ and v₃ bands respectively. Such crossing measurements allow us to determine experimentally, for the first time, the line strengths of 31 absorption lines of the ν1 band of trans isomer of nitrous acid that significantly impacts the air quality and climate change because of its crucial role in the atmospheric oxidation capacity. The QCL spectrometer is also deployed for continuous monitoring of methane (CH₄) during January 2013 in Dunkirk. Methane concentration variation is analyzed with the help of the simultaneously recorded meteorological parameters. In order to identify the sources of CH₄ emission, I developed an Isotope Ratio Laser Spectrometry (IRLS) technique to measure the isotopic ratio of ¹³CH₄/¹²CH₄. Preliminary results are presented

La demande en capacité liée à la transmission de tout type d’information (voix, vidéos, données, etc.) ne cesse de croître. Afin de répondre à cette demande croissante, de nouvelles générations de systèmes de communication multiplexés en longueur d’onde transmettant des débits élevés d’information par canal (100 Gbit/s ou plus) doivent être conçues. En plus des fibres ayant de très faibles pertes, des amplificateurs à fibre dopée à l’Erbium et du multiplexage en longueur d’onde, des technologies sont mises en place, comme notamment le multiplexage en polarisation, la détection cohérente, les formats de modulation multi-niveaux et plus récemment le multiplexage spatial. Des interrogations résident sur l’impact du multiplexage en polarisation ainsi qu’un développement vers des formats de modulation plus évolués incluant modulation de phase et multiplexage en polarisation. Dans cette thèse, afin de contribuer à l’augmentation du produit capacité x distance dans les systèmes de transmission Nx100 Gbit/s par fibre optique également multiplexés en polarisation et utilisant la détection cohérente, nous avons étudié d’une part, la mise en forme spectrale des signaux à l’émission pour augmenter la densité spectrale d’information (ISD: Information Spectral density). Dans cette optique, nous avons étudié l’impact du filtrage étroit gaussien du second ordre et de la mise en forme spectrale en racine de cosinus surélevé (RRC: Root Raised Cosine) sur les signaux émis dans le cas de modulations en Polarization Division Multiplexed-Quaternary Phase Shift Keying (PDM-QPSK) et Polarization-Switched-Quaternary Phase Shift Keying (PS-QPSK). Ceci a été réalisé en simulation numérique en considérant un espacement spectral entre les différents canaux variable. Nous avons montré qu’en tenant compte à la fois du facteur de qualité maximal et de la densité spectrale d’information, l’application de la mise en forme RRC sur des signaux modulés en PS-QPSK, fournit de meilleures performances de transmission dans une configuration où toute la dispersion est compensée en fin de propagation, pour toutes les valeurs d’espacement spectral étudiées. D’autre part, nous nous sommes intéressés aux effets non-linéaires qui limitent la portée de ces systèmes en dégradant pendant la propagation, les symboles émis, par les interactions entre des symboles d’un même canal, entre canaux ou modes de polarisation. La compréhension et la réduction de l’impact des effets non-linéaires est indispensable lorsqu’on veut utiliser certaines technologies pour augmenter la densité spectrale d’information. L’utilisation du multiplexage en polarisation par exemple, se heurte aux dégradations causées par les effets non-linéaires car de nouvelles interactions entre symboles sont présentes pendant la propagation. Par conséquent le développement des futurs systèmes ayant des débits plus élevés de 400 Gbit/s et 1 Tbit/s par canal passe par une diminution de l’impact des effets non-linéaires. Nous avons établi dans ce travail de thèse, des règles de conception permettant de réduire l’impact des effets non-linéaires entre polarisation dans les systèmes de transmission optiques considérés
The ever-increasing demand of capacity in very high bit rate coherent optical transmission systems has paved the way towards the investigation of several techniques such as the use of ultra-low loss fibers, Erbium doped fiber amplifiers, polarization and wavelength division multiplexing (WDM), coherent detection, multi-level modulation formats, spatial division multiplexing, etc. However, there are questions concerning polarization division multiplexing and a development towards some advanced modulation formats including phase modulation and polarization division multiplexing. In this thesis, in order to increase the capacity-by-distance product of future optical coherent systems using wavelength and polarization division multiplexing, we first study spectral shaping of the transmitted signals to increase the information spectral density. For this purpose, we have numerically investigated the multi-channel transmission performance of Polarization Switched Quadrature Phase Shift Keying (PSQPSK) and we have compared it to the performance of Polarization-Division-Multiplexed QPSK (PDM-QPSK), using Root Raised Cosine (RRC) spectral shaping, in the context of a flexible channel grid. In addition we have presented the advantage of PS-QPSK against PDM-QPSK as a function of the system parameters, while we have also discussed the benefit of a RRC spectral shaping against a tight filtering at the transmitter side with a 2nd order super-Gaussian-shaped filter. Furthermore, we have focused on nonlinear effects that limit the transmission distance by degrading the transmitted symbols during propagation. Analyzing and reducing the impact of nonlinear effects is essential when using technologies that increase the information spectral density such as polarization division multiplexing which causes new nonlinear effects due to additional interactions between symbols during the propagation through the fiber. Therefore a reduction of the impact of nonlinear effects is necessary for the development of future systems with higher bit rates of 400 Gbit/s and 1 Tbit/s per channel. We have established in this thesis, design rules to reduce the impact of nonlinear effects in the optical WDM transmission systems at 100 Gbit/s per channel that use polarization multiplexing

La forte demande et le besoin d’intégration hétérogène de nouvelles fonctionnalités dans les systèmes mobiles et autonomes, tels que les mémoires, capteurs, et interfaces de communication doit prendre en compte les problématiques d’hétérogénéité, de consommation d’énergie et de dissipation de chaleur. Les systèmes mobiles intelligents sont déjà dotés de plusieurs composants de type capteur comme les accéléromètres, les thermomètres et les détecteurs infrarouge. Cependant, jusqu’à aujourd’hui l’intégration de capteurs chimiques dans des systèmes compacts sur puce reste limitée pour des raisons de consommation d’énergie et dissipation de chaleur principalement. La technologie actuelle et fiable des capteurs de gaz, les résistors à base d’oxyde métallique et les MOSFETs (Metal Oxide Semiconductor- Field Effect Transistors) catalytiques sont opérés à de hautes températures de 200–500 °C et 140–200 °C, respectivement. Les transistors à effet de champ à grille suspendu (SG-FETs pour Suspended Gate-Field Effect Transistors) offrent l’avantage d’être sensibles aux molécules gazeuses adsorbées aussi bien par chemisorption que par physisorption, et sont opérés à température ambiante ou légèrement au-dessus. Cependant l’intégration de ce type de composant est problématique due au besoin d’implémenter une grille suspendue et l’élargissement de la largeur du canal pour compenser la détérioration de la transconductance due à la faible capacité à travers le gap d’air. Les transistors à double grilles sont d’un grand intérêt pour les applications de détection de gaz, car une des deux grilles est fonctionnalisée et permet de coupler capacitivement au canal les charges induites par l’adsorption des molécules gazeuses cibles, et l’autre grille est utilisée pour le contrôle du point d’opération du transistor sans avoir besoin d’une structure suspendue. Les transistors monoélectroniques (les SETs pour Single Electron Transistors) présentent une solution très prometteuse grâce à leur faible puissance liée à leur principe de fonctionnement basé sur le transport d’un nombre réduit d’électrons et leur faible niveau de courant. Le travail présenté dans cette thèse fut donc concentré sur la démonstration de l’intégration 3D monolithique de SETs sur un substrat de technologie CMOS (Complementary Metal Oxide Semiconductor) pour la réalisation de la fonction capteurs de gaz très sensible et ultra basse consommation d’énergie. L’approche proposée consiste à l’intégration de SETs métalliques à double grilles dans l’unité de fabrication finale BEOL (Back-End-Of-Line) d’une technologie CMOS à l’aide du procédé nanodamascene. Le système sur puce profitera de la très élevée sensibilité à la charge électrique du transistor monoélectronique, ainsi que le traitement de signal et des données à haute vitesse en utilisant une technologie de pointe CMOS disponible. Les MOSFETs issus de la technologie FD-SOI (Fully Depleted-Silicon On Insulator) sont une solution très attractive à cause de leur pouvoir d’amplification du signal quand ils sont opérés dans le régime sous-le-seuil. Ces dispositifs permettent une très haute densité d’intégration due à leurs dimensions nanométriques et sont une technologie bien mature et modélisée. Ce travail se concentre sur le développement d’un procédé de fonctionnalisation d’un MOSFET FD-SOI comme démonstration du concept du capteur de gaz à base de transistor à double grilles. La sonde Kelvin a été la technique privilégiée pour la caractérisation des matériaux sensibles par le biais de mesure de la variation du travail de sortie induite par l’adsorption de molécules de gaz. Dans ce travail, une technique de caractérisation des matériaux sensibles alternative basée sur la mesure de la charge de surface est discutée. Pour augmenter la surface spécifique de l’électrode sensible, un nouveau concept de texturation de surface est présenté. Le procédé est basé sur le dépôt de réseaux de nanotubes de carbone multi-parois par pulvérisation d’une suspension de ces nanotubes. Les réseaux déposés servent de «squelettes» pour le matériau sensible. L’objectif principal de cette thèse de doctorat peut être divisé en 4 parties : (1) la modélisation et simulation de la réponse d’un capteur de gaz à base de SET à double grilles ou d’un MOSFET FD-SOI, et l’estimation de la sensibilité ainsi que la puissance consommée; (2) la caractérisation de la sensibilité du Pt comme couche sensible pour la détection du H[indice inférieur 2] par la technique de mesure de charge de surface, et le développement du procédé de texturation de surface de la grille fonctionnalisée avec les réseaux de nanotubes de carbone; (3) le développement et l’optimisation du procédé de fabrication des SETs à double grilles dans l’entité BEOL d’un substrat CMOS; et (4) la fonctionnalisation d’un MOSFET FD-SOI avec du Pt pour réaliser la fonction de capteur de H[indice inférieur 2].
Abstract : The need of integration of new functionalities on mobile and autonomous electronic systems has to take into account all the problematic of heterogeneity together with energy consumption and thermal dissipation. In this context, all the sensing or memory components added to the CMOS (Complementary Metal Oxide Semiconductor) processing units have to respect drastic supply energy requirements. Smart mobile systems already incorporate a large number of embedded sensing components such as accelerometers, temperature sensors and infrared detectors. However, up to now, chemical sensors have not been fully integrated in compact systems on chips. Integration of gas sensors is limited since most used and reliable gas sensors, semiconducting metal oxide resistors and catalytic metal oxide semiconductor- field effect transistors (MOSFETs), are generally operated at high temperatures, 200–500 °C and 140–200° C, respectively. The suspended gate-field effect transistor (SG-FET)-based gas sensors offer advantages of detecting chemisorbed, as well as physisorbed gas molecules and to operate at room temperature or slightly above it. However they present integration limitations due to the implementation of a suspended gate electrode and augmented channel width in order to overcome poor transconductance due to the very low capacitance across the airgap. Double gate-transistors are of great interest for FET-based gas sensing since one functionalized gate would be dedicated for capacitively coupling of gas induced charges and the other one is used to bias the transistor, without need of airgap structure. This work discusses the integration of double gate-transistors with CMOS devices for highly sensitive and ultra-low power gas sensing applications. The use of single electron transistors (SETs) is of great interest for gas sensing applications because of their key properties, which are its ultra-high charge sensitivity and the ultra-low power consumption and dissipation, inherent to the fundamental of their operation based on the transport of a reduced number of charges. Therefore, the work presented in this thesis is focused on the proof of concept of 3D monolithic integration of SETs on CMOS technology for high sensitivity and ultra-low power gas sensing functionality. The proposed approach is to integrate metallic double gate-single electron transistors (DG-SETs) in the Back-End-Of-Line (BEOL) of CMOS circuits (within the CMOS interconnect layers) using the nanodamascene process. We take advantage of the hyper sensitivity of the SET to electric charges as well from CMOS circuits for high-speed signal processing. Fully depleted-silicon on insulator (FD-SOI) MOSFETs are very attractive devices for gas sensing due to their amplification capability when operated in the sub-threshold regime which is the strongest asset of these devices with respect to the FET-based gas sensor technology. In addition these devices are of a high interest in terms of integration density due to their small size. Moreover FD-SOI FETs is a mature and well-modelled technology. We focus on the functionalization of the front gate of a FD-SOI MOSFET as a demonstration of the DGtransistor- based gas sensor. Kelvin probe has been the privileged technique for the investigation of FET-based gas sensors’ sensitive material via measuring the work function variation induced by gas species adsorption. In this work an alternative technique to investigate gas sensitivity of materials suitable for implementation in DG-FET-based gas sensors, based on measurement of the surface charge induced by gas species adsorption is discussed. In order to increase the specific surface of the sensing electrode, a novel concept of functionalized gate surface texturing suitable for FET-based gas sensors are presented. It is based on the spray coating of a multi-walled-carbon nanotubes (MW-CNTs) suspension to deposit a MW-CNT porous network as a conducting frame for the sensing material. The main objective of this Ph.D. thesis can be divided into 4 parts: (1) modelling and simulation of a DG-SET and a FD-SOI MOSFET-based gas sensor response, and estimation of the sensitivity as well as the power consumption; (2) investigation of Pt sensitivity to hydrogen by surface charge measurement technique and development of the sensing electrode surface texturing process with CNT networks; (3) development and optimization of the DG-SET integration process in the BEOL of a CMOS substrate, and (4) FD-SOI MOSFET functionalization with Pt for H[subscript 2] sensing.

L'acoustique picoseconde est une technique qui permet de générer et de détecter des ondes acoustiques de longueur d'onde submicrométrique par l'utilisation d'impulsions lumineuses ultrarapides (100 fs). Si la technique commence à être appliquée industriellement pour le contrôle non-destructif de films solides micrométriques, comme les microprocesseurs, très peu d'études concernent son application aux milieux liquides ou mous, malgré son potentiel unique pour les mesures acoustiques très hautes fréquences (supérieur à la dizaine de GHz). Ce travail de thèse dresse un premier panorama d'applications possibles de la technique d'acoustique picoseconde pour l'étude d'une cellule biologique unique, dont l'épaisseur peut être d'une centaine de nanomètres à quelques micromètres. Les résolutions atteintes permettent des applications pour l'imagerie et la tomographie acoustique d'une cellule unique par la détermination locale de ses propriétés physiques. Un modèle de simulation analytique est développé pour aider à la compréhension des signaux détectés et pour la résolution du problème inverse. La génération acoustique est simulée en résolvant les équations couplées de diffusion de la chaleur et de la propagation acoustique. La détection optique est ensuite étudiée en résolvant l'équation de Maxwell où les phénomènes thermiques et acoustiques perturbent l'indice optique du matériau. Pour les besoins expérimentaux, une enceinte biologique, étanche et thermostatée, est conçue. De même, le montage laser est adapté pour permettre une détection bicolore de l'onde acoustique se propageant dans la cellule. Enfin, un microscope combinant la visualisation des cellules par épifluorescence au dispositif laser expérimental est développé. Ce dernier permet de localiser précisément les éléments subcellulaires de la cellule, pour ensuite les étudier par acoustique picoseconde. La démonstration du potentiel de la méthode pour l'imagerie cellulaire et l'évaluation de sa sensibilité est faite sur cellule végétale. Ensuite, une mesure quantitative des propriétés viscoélastiques de cellules ostéoblastes (MC3T3-E1), adhérentes sur un matériau mimant une prothèse de titane, est réalisée. Puis, l'effet du peptide RGD et de la protéine BMP-2 sur les propriétés viscoélastiques de la cellule ostéoblaste est quantifié. Ce travail est réalisé en partenariat avec une équipe de recherche en bio-ingénierie et reconstruction tissulaire, l'U577.

L'objectif de ce travail de thèse est de développer une sonde optique dédiée à aider le neurochirurgien à parfaire la résection des glioblastomes. Ce type de tumeurs est le plus fréquent et le plus agressif. Améliorer son exérèse permettrait d'augmenter la durée de survie moyenne du patient. Une exposé des tumeurs cérébrales et de leur prise en charge médicale introduit cette thèse. Le développement comporte trois volets. En premier lieu, le dispositif expérimental et la sonde utilisée fibrée sont caractérisés. Pour ce faire, des fantômes optiques calibrés aux géométries variées ont été conçus. Après validation, ils ont permis de définir la profondeur détectée en fonction de la variation de coefficients optiques.Deuxièmement, un programme de simulation Monte-Carlo a été développé et adapté au dispositif de mesures. Grâce aux mesures sur fantômes, ce programme a été validé. Cet outil permet un gain de temps considérable dans le processus de définition des propriétés de détection d'une sonde en fonction de sa géométrie.Enfin, dans le but d'identifier des indicateurs potentiels du tissu cérébral tumoral, une campagne de mesures sur modèle animal a été menée. Une étude spectroscopique approfondie a été effectuée sur des échantillons frais ex vivo. Plusieurs indices caractéristiques des tissus tumoraux ont été mis en évidence grâce à ce travail.

碩士
國立臺灣大學
機械工程學研究所
102
In aging society nowadays, fall down of elders is a serious social problem. According to the data of CDC (Centers for Disease Control and Prevention), in death cases of injuries, half death cases result from unintentional falls. Besides, the medical costs with regard to falls reach up to 30 billion US dollars per year in the US. Also, because the decline of physical and reaction abilities of elders, elders tend to fall especially. As a result, designing an automated system to prevent falls from happening or send alarms for help after falls happened becomes a critical problem in the development of technologies recent years. Scientists and Engineers have dedicated to develop technologies to prevent falls, including wearable devices and ambience devices, these devices has various application and their pros and cons. In this thesis, a camera-based line-laser obstacle detection system is proposed. Before elders kick on obstacles to fall, this system can emit alarm messages to mention them and then reach the goal to prevent falls, to prevent the damage on the bodies and the negative impacts to the mind of elders, finally to save medical costs of the whole society. Because elders spend most of their time at home or in nursing homes, most fall cases occur indoors. Therefore, the proposed line-laser obstacle detection system is designed mainly for indoor applications. The camera based line-laser obstacle detection system cast its line-laser on a horizontal plane which has a specific height to the ground. And then the system uses a camera which has an angle to the plane to extract the line-laser pattern. Under this system configuration, when the depth of obstacles in front of the system changes, the extracted line-laser pattern in the image will have disparities. This system uses the characteristic of disparities to detect the distance of obstacles from the system. In real implementation, system will be triggered when users step on the ground or when users raise the foot at max height during a gait cycle. This enables the system to detect obstacles on the ground or higher obstacles. In our method, differences between frames are utilized to determine the trigger time of our line-laser obstacle detection system. After the system was triggered, the captured frame will be filtered with a median filter first, and then the line-laser pattern on the image will be extracted. At the same time, an intensity threshold is used to separate the line-laser pattern from background in order to get a better line-laser pattern extraction result. On the extracted line-laser pattern, the deviation between the present pixel and the last pixel is utilized to classify each pixel to the cluster which denotes a specific obstacle, and a deviation threshold is set to implement image segmentation. And then a tangent line with a specific threshold on histogram is used to distinguish clusters which denote obstacles from clusters which come from noise. Last, we implement homography matrix to transform the coordinate on the image into the coordinate on the detection plane. Therefore, the depth and the width of each obstacle can be calculated to judge how dangerous this obstacle is. If any obstacle is too dangerous, an alarm message will be emitted to prevent elders from falling. Among algorithms of line-laser obstacle detection system, some parameters and thresholds of the system need to be determined. As a result, some experiments are designed to suggest suitable parameters and thresholds for system operation. Furthermore, a validation of homography which computes the distance between obstacles and the system is carried out. The result shows that the error of homography distance computation can fulfill the need of obstacle detection. Keywords: Obstacle detection, line-laser, homography, disparity, image segmentation

Coherent plane-wave compounding (CPWC) ultrasound is an important modality enabling ultrafast biomedical imaging. To perform CWPC image reconstruction for a stratified (horizontally layered) medium, one needs to know how the speed of sound (SOS) varies with the propagation depth. Incorrect sound speed and layer thickness assumptions can cause focusing errors, degraded spatial resolution and significant geometrical distortions resulting in poor image reconstruction. We aim to determine the speed of sound and thickness values for each horizontal layer to accurately locate the recorded reflection events to their true locations within the medium. Our CPWC image reconstruction process is based on phase-shift migration (PSM) that requires the user to specify the speed of sound and thickness of each layer in advance. Prior to performing phase-shift migration (one layer at a time, starting from the surface), we first estimate the speed of sound values of a given layer using a cosine similarity metric, based on the data obtained by a multi-element transducer array for two different plane-wave emission angles. Then, we use our speed estimate to identify the layer thickness via end-of-layer boundary detection. A low-cost alternative that obtains reconstructed images with fewer phase shifts (i.e., fewer complex multiplications) using a spectral energy threshold is also proposed in this thesis. Our evaluation results, based on the CPWC imaging simulation of a three-layer medium, show that our sound speed and layer thickness estimates are within 4% of their true values (i.e., those used to generate simulated data). We have also confirmed the accuracy of our speed and layer thickness estimation separately, using two experimental datasets representing two special cases. For speed estimation, we used a CPWC imaging dataset for a constant-speed (i.e., single-layer) medium, yielding estimates within 1% of their true values. For layer thickness estimation, we used a monostatic (i.e., single-element) synthetic-aperture (SA) imaging dataset of the three-layer medium, also yielding estimates within 1% of their true values. Our evaluation results for the low-cost alternative showed a 93% reduction in complex multiplications for the three-layer CPWC imaging dataset and 76% for the three-layer monostatic SA imaging dataset, producing images nearly similar to those obtained using the original PSM methods.
Graduate

Amperometric and coulometric reticulated vitreous carbon (RVC) detectors were constructed and evaluated for detection in flow injection analysis. These detectors offer a wide range of fraction conversion up to 100%. The flow rate dependency of the current was studied and compared with porous electrode theory. The precision, analytical range, band-broadening, and detection limits are comparable to that of other glassy carbon amperometric detectors. Pulsed flow electrolysis with the RVC electrode was developed for amperometry and voltammetry using lock-in amplification to measure the a.c. response which is independent of the large background current. Linearity and detection limits were determined and factors affecting the detection limits were investigated. The RVC electrode was shown to have rapid diffusion layer relaxation due to high conversion and thin layer electrolysis. Computer calculations of thin layer electrolysis were used to predict the mass transfer properties of the electrode and the results were compared with those of other electrode geometries. A new on-line system for studying the secretion of catecholamines from stimulated bovine adrenal cells in culture allows greater precision in kinetic measurements of the onset of secretion and the desensitization. The low-volume system uses flow injection analysis with which variable amounts of stimulant injected into the flowline pass through a packed bed of microbeads to which the cells are attached and the secreted catecholamines are electrochemically detected downstream. The low dispersion of the system provides low distortion of the secretory response and good detection limits. The desensitization in the presence of long-term stimulation with acetylcholine at room temperature was first order. Dramatic differences in the amount secreted and the recovery time of the cells were found at physiological temperature. Studies of secretion in the presence of nucleotides and varying concentrations of calcium revealed a depression of secretion in the presence of ATP and a minimum rate of desensitization in 1 mM calcium. More catecholamine was secreted in the absence of sodium than in its presence. The versatility of the technique for investigating desensitization and secretion due to one affector in the presence of another was demonstrated.