Optical sensor systems that integrate Long-Period-Gratings (LPG) as the detection arm have been proven to be highly sensitive and reliable in many applications. With increasing public recognition of threats from bacteria-induced diseases and their potential outbreak among densely populated communities, an intrinsic, low-cost biosensor device that can perform quick and precise identification of the infection type is in high demand to respond to such challenging situations and control the damage those diseases could possibly cause. This dissertation describes the development of a biosensor platform that utilizes polymer thin films, known as ionic self-assembled multilayer (ISAM) films, to be the sensitivity- enhancing medium between an LPG fiber and specific, recognition layer. With the aid of cross- linking reactions, monoclonal antibodies (IgG) or DNA probes are immobilized onto the surface of the ISAM-coated fiber, which form the core component of the biosensor. By immersing such biosensor fiber into a sample suspension, the immobilized antibody molecules will bind the specific antigen and capture the target cells or cell fragments onto the surface of the fiber sensor, resulting in increasing the average thickness of the fiber cladding and changing the refractive index of the cladding. This change occurring at the surface of the fiber results in a decrease of optical power emerging from the LPG section of the fiber. By comparing the transmitted optical power before and after applying the sample suspension, we are able to determine whether or not certain bacterial species have attached to the surface of the fiber, and as a consequence, we are able to determine whether or not the solution contains the targeted bacteria. This platform has the potential for detection of a wide range of bacteria types. In our study, we have primarily investigated the sensitivity and specificity of the biosensor to methicillin- resistant Staphlococcus aureus (MRSA). The data we obtained have shown a sensitive threshold at as low as 102 cfu/ml with pure culture samples. A typical MRSA antibody-based biosensor assay with MRSA sample at this concentration has shown optical power reduction of 21.78%. In a detailed study involving twenty-six bacterial strains possessing the PBP2a protein that enables antibiotic resistance and sixteen strains that do not, the biosensor system was able to correctly identify every sample in pure culture samples at concentration of 104 cfu/ml. Further studies have also been conducted on infected mouse tissues and clinical swab samples from human ears, noses, and skin, and in each case, the system was in full agreement with the results of standard culture tests. However, the system is not yet able to correctly distinguish MRSA and non-MRSA infections in clinical swab samples taken from infected patient wounds. It is proposed that nonspecific binding due to insufficient blocking methods is the key issue. Other bacterial strains, such as Brucella and Francisella tularensis have also been studied using a similar biosensor platform with DNA probes and antibodies, respectively, and the outcomes are also promising. The Brucella DNA biosensor is able to reflect the existence of 3 Brucella strains at 100 cfu/ml with an average of 12.2% signal reduction, while negative control samples at 106cfu/ml generate an average signal reduction of -2.1%. Similarly, the F. tularensis antibodies biosensor has shown a 25.6% signal reduction to LVS strain samples at 100 cfu/ml, while for negative control samples at the same concentration, it only produces a signal reduction of 0.05%. In general, this biosensor platform has demonstrated the potential of detecting a wide range of bacteria in a rapid and relatively inexpensive manner. / Ph. D.

Pendant l’Antiquité, l’espace compris entre la Moselle et le Rhin est une zone où se déroulent de nombreux événements historiques qui modifient successivement son organisation administrative et politique. Cette thèse a pour objectif d’étudier, à partir d’une approche spatiale, modélisatrice et comparative, l’évolution du peuplement de quatre micro-régions au sein de ce vaste espace du Ier s. av. J.-C. au Ve s. ap. J.-C. Dans ces cadres sont étudiés successivement, la forme et la dynamique des habitats, la structuration des espaces qu’ils produisent et enfin, les modalités d’implantation. Les résultats mettent en évidence la diversité des types d’habitats, des configurations spatiales et des dynamiques. Les campagnes ne sont pas uniformes et les mécanismes qui influencent la formation et la trajectoire des différents types de profils perçus sont complexes. Ils dépendent autant de facteurs locaux que de phénomènes historiques globaux. Les différentes situations décrites permettent aussi de constater que les campagnes suivent des processus d’évolutions longs qui ne débutent ou qui ne s’achèvent pas aux limites des périodes historiques définies. / During the Antiquity, the space between the Moselle and the Rhine is an area in which many historical events occured. Those events successively changed its administrative and political organization. This dissertation aims to study, through spatial, model, and comparative approaches, the evolution of the settlement of four micro-regions within a vast space between the I. c. BC to the V c. AD. In these frameworks, the shape and dynamics of the habitat, the structuring spaces they generate, and finally, the establishment choices of the settlements are consecutively studied. The results highlight the diversity of habitat types, spatial patterns and dynamics. The countrysides are not uniform and the mechanisms influencing the formation and the trajectory of the different types of perceived patterns are complex. They equally depend from many local factors and from the global historical phenomenon. The variety of cases described in this dissertation enables us to see that the countrysides are following several long evolution processes. The latter do not begin or finish on the borders of the defined historical periods.

Les séismes de type longue période (LP) sont aujourd’hui enregistrés sur la plupart des volcans dans le monde entier. Malgré cela, le mécanisme à leur source n’est encore que très peu compris. A l’heure actuelle les modèles proposés pour expliquer leur origine sont : 1) la résonance d’une fracture remplie de gaz ou de fluides excités par des instabilités dans l’écoulement des fluides ou par la rupture fragile du magma ; 2) la fracturation lente des sédiments peu consolidés à la surface des volcans, dans des conditions de transition entre le ductile et le fragile. L’outil le plus utilisé pour comprendre leur nature est aujourd’hui l’inversion du tenseur des moments. Au cours des dernières années, les inversions du tenseur des moments se concentraient principalement sur la compréhension du mécanisme physique à l’origine des séismes LP qui souvent supposaient des milieux géologiques très simples, voire homogènes. Des études récentes ont montré l’influence des sédiments peu consolidés à la surface des volcans sur la propagation des ondes à basse fréquence et en conséquence, sur l’inversion du tenseur des moments quand ils ne sont pas pris en compte dans le processus d’inversion. Le but de cette thèse est de mieux comprendre les processus physiques qui génèrent les séismes LP et de quantifier les incertitudes liées à leur interprétation. / Long-period (LP) seismic events are abundantly recorded during rest and unrest periods at many volcanoes worldwide. However, their source mechanism is still poorly understood. Models which have been proposed so far to explain their origin are: 1) the resonance of a fluid-filled cavity triggered by fluid instabilities or the brittle failure of magma; 2) slow-rupture earthquakes occurring in the low consolidated materials composing the shallow portion of the volcanic edifice. Nowadays the main tool used to get insights into their nature is moment tensor (MT) inversion. MT inversions carried out in the past years focused mainly on the understanding of the physical origin of LP events and often supposed a relative simple geological structure of the medium. Recent studies highlighted the strong influence of shallow unconsolidated materials on the retrieved MT solutions and the importance of considering geological inhomogeneity in the inversion process. The principal aim of this thesis is to gain a better understanding of the source processes that generate LP events and to quantify the uncertainties related to the MT inversion process.

Made available in DSpace on 2016-12-01T19:18:48Z (GMT). No. of bitstreams: 1 Arthurcapa.pdf: 114460 bytes, checksum: 074e7575046f56b1e5f955ab1efa7f53 (MD5) Previous issue date: 2009-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study intends to evaluate the applicability of Grumbach´s method of construction of sceneries on formulating strategies for the LocalX Company. The theoretical referencial picture included contents related to the formal organizations, to the external atmosphere, to organizational strategies and prospective methods of construction of sceneries. The research is a kind of exploratory, descriptive and applied. The techniques of data collection used in the development of the work were interview not structured, documental analysis, observation and questionnaire. Collected data and information were treated through Puma software, a computerized application. The conclusions demonstrate Grumbach´s method as extremely valuable tool for providing larger knowledge regarding uncertainties in the organizational atmosphere, allowing to manager make decisions with more quality, creativity, safety and agility. Other several benefits were revealed - creation of a systemic vision of the managerial team; unification of the organizational language; expansion of net information; updating the capacity observation of the atmosphere; creation of an interdependent and harmonic vision. The uncertainties - if understood as future possibilities can increase his/her understanding and minimize the surprises and eventual jolts. Drawning sceneries with his/her several tendencies, a team with systemic and aligned vision gets easily understanding the events quickly reacting in the sense of minimizing any threat or to take advantage at any presented opportunity. In other words, the method allows the leaders to think strategies about long period and apply them in the day by day / O estudo propõe-se avaliar a aplicabilidade do método de construção de cenários proposto por Grumbach na formulação de estratégias para a empresa LocalX. O quadro referencial teórico abrangeu conteúdos relacionados às organizações formais, ao ambiente externo, a estratégias organizacionais e a métodos prospectivos de construção de cenários. A pesquisa é do tipo exploratório, descritiva e aplicada. As técnicas de coleta de dados utilizadas no desenvolvimento do trabalho foram a entrevista não estruturada, a análise documental, a observação e o questionário. Os dados e as informações coletados foram tratados por meio da aplicação de software informatizado, denominado Puma. As conclusões demonstram que o método de Grumbach é uma ferramenta extremamente valiosa em função de proporcionar maior conhecimento a respeito das incertezas do ambiente organizacional, permitindo ao gestor tomar decisões de maior qualidade, criatividade, segurança e agilidade. Outros benefícios foram revelados: criação de uma visão sistêmica da equipe gerencial; unificação da linguagem organizacional; expansão da rede de informações; aprimoramento da capacidade de observação do ambiente; criação de uma visão interdependente e harmônica. As incertezas, se entendidas como possibilidades de futuro, aumentam sua compreensão e minimizam as surpresas e os solavancos. Com os cenários traçados e com seus diversos acompanhamentos, uma equipe com visão sistêmica e alinhada consegue facilmente compreender os acontecimentos e reagir rapidamente no sentido de minimizar qualquer ameaça ou aproveitar qualquer oportunidade apresentada. Em outras palavras, o método permite que os dirigentes pensem as estratégias em longo prazo e as apliquem no dia-a-dia

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-10-02T19:31:50Z No. of bitstreams: 1 felipedesouzadelgado.pdf: 2621698 bytes, checksum: f2d2c40acc8fdf80a70c9f39aabc0cc9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-10-09T19:46:37Z (GMT) No. of bitstreams: 1 felipedesouzadelgado.pdf: 2621698 bytes, checksum: f2d2c40acc8fdf80a70c9f39aabc0cc9 (MD5) / Made available in DSpace on 2017-10-09T19:46:37Z (GMT). No. of bitstreams: 1 felipedesouzadelgado.pdf: 2621698 bytes, checksum: f2d2c40acc8fdf80a70c9f39aabc0cc9 (MD5) Previous issue date: 2017-08-24 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação apresenta a produção de redes de período longo em fibras ópticas por descargas de arcos elétricos e o seu uso em aplicações de sensoriamento de corrente em veículos aéreos não tripulados. Os aspectos teóricos fundamentais para o entendimento das redes de período longo são apresentados. Além disso, discutiu-se os diferentes tipos de acoplamentos de energia que podem ocorrer em uma rede de período longo e também, os mecanismos responsáveis pela formação dessas redes produzidas por descargas de arco elétrico. A fabricação de redes de período longo utilizando a técnica de arco elétrico foi descrita e o comportamento da perda dependente da polarização das redes produzidas foi investigado. Além disso, é apresentado um novo método para a produção de redes de período longo com perda dependente da polarização reduzida. Constatou-se que por meio de alterações no ângulo de incidência das descargas elétricas na fibra óptica em relação à um ponto de referência, é possível promediar os efeitos induzidos pontualmente por cada descarga de arco elétrico e assim, reduzir a perda dependente da polarização intrínseca dessas redes. Por fim, é apresentada a aplicação de uma rede produzida por arco elétrico combinada a um ímã de neodímio, compondo um novo dispositivo de sensoriamento para medir a corrente elétrica exigida pelos motores elétricos de um veículo aéreo não tripulado. / This dissertation presents the fabrication of long-period fiber gratings through electric arc discharges and their application in current sensing in unmanned aerial vehicles. The theoretical aspects of long-period gratings are presented. Besides, we discussed the different types of coupling that could occur in a long-period fiber grating, as well as the mechanisms responsible for the formation of the gratings produced by electric arc discharges. The manufacture process of the long-period gratings using the electric arc technique was described and the behavior of the polarization dependent loss of these gratings was investigated. In addition, a new method for the production of long period gratings with reduced polarization dependent loss is introduced. It has been found that by changing the incidence angle of the electric discharges in the optical fiber in relation to a reference point, it is possible to average the effects induced by each electric arc discharge and, therefore, reducing the intrinsic polarization dependent loss of these gratings. Finally, the application of a grating produced by electric arc combined with a neodymium permanent magnet is presented. This combination allows us to measure the electric current required by a motor of an unmanned aerial vehicle.

[ES] La fibra óptica ha supuesto una gran revolución en el mundo de las telecomunicaciones debido a su alta capacidad de transmisión y sus bajas pérdidas. Hoy en día no sería posible transportar la cantidad de tráfico que se genera en internet si no fuera por sis- temas de comunicaciones basados en fibras ópticas. Sin embargo, el número de dispo- sitivos conectados a internet es cada vez mayor, por lo que la capacidad de la fibra óptica estándar de un solo núcleo se puede ver limitada en un futuro no muy lejano. Una forma de aumentar dicha capacidad es utilizar fibras ópticas con varios núcleos. Actualmente existe un gran interés sobre la investigación en este tipo de fibras para aplicaciones de telecomunicaciones, por lo que no es difícil encontrar fibras multinú- cleo comerciales. Aunque el uso más común de la fibra óptica es para telecomunicaciones, también se puede utilizar como sensor. Uno de los métodos más comunes para la implementa- ción de sensores es la inscripción de redes de difracción en fibras ópticas de un solo núcleo. Sin embargo, la inscripción de redes de dirección en fibras de múltiples núcleos abre nuevas líneas de investigación para el desarrollo de sensores avanzados. En esta tesis se ha estudiado distintos tipos de redes de difracción inscritas en una fibra de siete núcleos para su aplicación en la implementación de sensores. En primer lugar, se describe el sistema de fabricación que permite inscribir distintos tipos de redes de difracción en la fibra multinúcleo de forma selectiva, es decir, permite seleccionar en que núcleos se va a inscribir la red. Mediante este sistema se han inscrito redes de periodo largo y posteriormente se han caracterizado como sensor de deformación, tor- sión y curvatura. Después, se han inscrito redes de Bragg inclinadas para aumentar de forma intencionada la diafonía entre los núcleos de la fibra mediante el acoplo de luz entre ellos. Además, se ha demostrado experimentalmente que esta diafonía es sensible a la deformación de la fibra, a la curvatura, a la temperatura y al índice de refracción que rodea la fibra. Por otro lado, se ha demostrado que las redes de Bragg inscritas en fibras multinúcleo se pueden utilizar para implementar sensores de curvatura capaces de operar en entornos radioactivos. Finalmente se han fabricado redes de Bragg rege- neradas capaces de operar a altas temperaturas, estas redes se han caracterizado como sensor de temperatura, deformación y curvatura. / [CAT] La fibra òptica ha suposat una gran revolució en el món de les telecomunicacions a causa de la seua alta capacitat de transmissió i les seues baixes pèrdues. Hui en dia no seria possible transportar la quantitat d'informació que es genera en internet si no fos pels sistemes de comunicacions basats en fibres òptiques. No obstant això, el nombre de dispositius connectats a internet es cada vegada més gran, per la qual cosa la capacitat de la fibra òptica estàndard d'un sol nucli es pot veure limitada en un futur no gaire llunyà. Una manera d'augmentar aquesta capacitat es utilitzar fibres òptiques amb diversos nuclis. Actualment existeix un gran interès sobre la investigació en aquesta mena de fibres per a aplicacions de telecomunicacions, per la qual cosa no es difícil trobar fibres de múltiples nuclis comercials. Encara que l'ús mes comú de la fibra òptica es per a telecomunicacions, també es pot utilitzar com a sensor. Un dels mètodes més comuns per a la implementació de sensors es la inscripció de xarxes de difracció en fibres òptiques d'un sol nucli. No obstant això, la inscripció de xarxes de difracció en fibres de múltiples nuclis obri noves línies d'investigació per al desenvolupament de sensors més complexos. En aquesta tesi s'ha estudiat diferents tipus de xarxes de difracció inscrites en una fibra de set nuclis per a la seua aplicació en la implementació de sensors en fibra òptica. En primer lloc, es descriu el sistema de fabricació de xarxes de difracció que permet inscriure diferents tipus de xarxes de difracció en la fibra de múltiples nuclis de manera selectiva, es a dir, permet seleccionar en que nuclis s'inscriurà la xarxa. Mitjançant aquest sistema s'han inscrit xarxes de període llarg i posteriorment s'han caracteritzat com a sensor de deformació, torsió i curvatura. Després, s'han inscrit xarxes de Bragg inclinades per a augmentar de manera intencionada la diafonia entre els nuclis de la fibra mitjançant l'acoblament de llum entre ells. A més d'això, s'ha demostrat experimentalment que aquesta diafonia es sensible a la deformació de la fibra, a la curvatura, a la temperatura i a l'índex de refracció que envolta la fibra. D'altra banda, s'ha demostrat que les xarxes de Bragg inscrites en fibres múltiples nuclis es poden utilitzar per a implementar sensors de curvatura que poden operar en entorns radioactius. Finalment s'han fabricat xarxes de Bragg regenerades que suporten altes temperatures, aquestes xarxes s'han caracteritzat com a sensor de temperatura, deformació i curvatura. / [EN] Optical fiber has been a great revolution in the world of telecommunications due to its high transmission capacity and low attenuation. Today it would not be possible to transport the amount of traffic that is generated on the Internet without communication systems based on optical fibers. However, the number of devices connected to the Internet is increasing, so the capacity of standard single-core fiber optics may be limited so far in the future. One way to increase this capacity is to use multi-core optical fibers. Nowadays is a great interest in research in this type of fibers for telecommunications applications, so it is not difficult to find commercial multicore fibers. Although the most common use of fiber optics is for telecommunications, it can also be used as a sensor. One of the most common methods for sensor implementation is the inscription of diffraction gratings on single-core optical fibers. However, the enrollment of steering networks in multi-core fibers opens new lines of research for the development of advanced sensors. In this thesis, different types of diffraction gratings inscribed in a seven-core fiber have been studied for their application in the implementation of sensors. In the first place, the diffraction grating manufacturing system is described that allows to inscribe different types of diffraction gratings in the multicore fiber selectively, that is, it allows to select in which cores the grating is going to be inscribed. By means of this system, long-period networks have been inscribed and subsequently they have been characterized as a deformation, torsion, and curvature sensor. Then, slanted Bragg gratings have been inscribed to intentionally increase the crosstalk between the fiber cores by coupling light between them. Furthermore, this crosstalk has been experimentally shown to be sensitive to fiber deformation, curvature, temperature, and the index of refraction surrounding the fiber. On the other hand, it has been shown that Bragg networks inscribed in multicore fibers can be used to implement curvature sensors capable of operating in radioactive environments. Finally, regenerated Bragg nets capable of operating at high temperatures have been manufactured. These nets have been characterized as a temperature, deformation, and curvature sensor. / Agradezco a la Universitat Politècnica de València la beca FPI (PAID-01-18) que me fue concedida para realizar está tesis. / Madrigal Madrigal, J. (2022). Diseño, fabricación y caracterización de sensores basados en fibras ópticas de múltiples núcleos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/180806 / TESIS

La découverte d’exoplanètes a connu une croissance quasi exponentielle au cours des trois dernières décennies. Nous savons désormais que les systèmes d’exoplanètes sont la norme dans la galaxie et qu’il existe une variété d’archétypes de planètes qui ne correspondent pas à notre propre système solaire. Ces progrès rapides sont dus en grande partie aux missions spatiales qui utilisent la méthode des transits pour trouver et caractériser de nouvelles exoplanètes. Kepler et, plus récemment, le Transiting Exoplanet Survey Satellite (TESS) ont contribué à la majorité des exoplanètes confirmées ou candidates connues à ce jour. Les exoplanètes découvertes par TESS sont particulièrement prometteuses, car TESS a délibérément ciblé des étoiles hôtes brillantes pour faciliter l’analyse spectroscopique détaillée de l’atmosphère de leurs planètes. Bien que TESS soit très efficace pour identifier de nouveaux signaux de transit, un effort de suivi substantiel est nécessaire pour valider chaque nouvelle candidate et le succès global de la mission TESS dépend fortement de l’obtention de ce suivi de la part d’observatoires externes. Une attention particulière est souvent requise pour les planètes à longue période qui souffrent fortement des biais impliqués dans les recherches de transit. Si l’on peut surmonter les défis observationnels supplémentaires, ces planètes constituent des bancs d’essai rares et précieux pour étudier la physique et la chimie des atmosphères plus froides. Dans cette thèse, j’ai collaboré avec la communauté de suivi des exoplanètes TESS sur plusieurs fronts en apportant des instruments précédemment inutilisés, en contribuant à l’effort général de vérification des candidates, ainsi qu’en menant des études de validation et de confirmation de cibles difficiles à longue période. Nous avons adapté le réseau de téléobjectifs Dragonfly (alias "Dragonfly"), conçu pour les cibles de faible luminosité de surface, à l’observation des transits d’exoplanètes. J’ai développé un nouveau mode d’observation adapté aux transits et créé des pipelines de planification, de traitement des données et d’analyse. Nous avons atteint une précision photométrique d’environ 0,5 ppt dans des intervalles de 4 à 5 minutes sur la plage 9 < mV < 13, compétitive avec d’autres observatoires au sol de classe 1–2 m. Nous avons également développé un vaste programme d’observation avec le satellite de surveillance des objets proches de la Terre (NEOSSat) couvrant 3 ans et 6 cycles d’observation pour observer les transits d’exoplanètes de longue durée, qui représentent un défi majeur à capturer avec des observatoires au sol. En utilisant ces deux instruments, nous avons fourni des observations pour le programme d’observation de suivi des exoplanètes TESS (ExoFOP). Grâce à mon travail dans ExoFOP, j’ai dirigé une publication de validation pour TOI-1221 b, une planète sub-neptunienne de 2,9 rayons terrestres sur une orbite de 92 jours. Non seulement nous avons écarté les scénarios de faux positifs pour cette planète tempérée à longue période, mais grâce à notre analyse détaillée de 6 transits TESS et 2 détections au sol, nous avons trouvé des preuves de variations de synchronisation de transit qui pourraient indiquer une autre planète cachée dans le système. Nous avons également utilisé NEOSSat pour rechercher un deuxième transit de TOI-2010 b, qui n’en montrait qu’un seul dans les données TESS. En surveillant l’étoile hôte sur une fenêtre d’incertitude de 7 jours, nous avons capturé le transit et amélioré considérablement notre connaissance de l’éphéméride de la planète. J’ai dirigé l’article de confirmation sur cette planète semblable à Jupiter avec une orbite de 142 jours, ajoutant une cible de faible insolation à la petite collection d’exoplanètes connues avec des périodes supérieures à 100 jours et des étoiles hôtes suffisamment brillantes pour un suivi spectroscopique. En plus de diriger ces deux projets spécifiques, mes observations avec Dragonfly et NEOSSat ont jusqu’à présent contribué à 10 autres publications dont je suis co-auteur. / Exoplanet discovery has undergone near-exponential growth over the last three decades. We now know exoplanet systems are the norm in the Galaxy and that a variety of planet archetypes exist that do not necessarily match our own Solar System. This rapid advancement is due in large part to space-based discovery missions utilizing the transit method to find and characterize new exoplanets. Kepler, and more recently, the Transiting Exoplanet Survey Satellite (TESS) have contributed the majority of confirmed or candidate exoplanets known today. The exoplanets discovered by TESS show particular promise, as TESS has deliberately targeted bright host stars to facilitate detailed spectroscopic analysis of their planets’ atmospheres. While TESS is highly efficient at identifying new transit signals, substantial follow-up effort is required to validate each new candidate and the overall success of the TESS mission heavily depends on attaining this follow-up from external observatories. Special attention is often required for long-period planets that suffer heavily from the biases involved in transit searches. If one can overcome the added observational challenges, these planets provide rare and valuable testbeds to investigate cool-atmosphere physics and chemistry. Through this thesis, I engaged with the TESS exoplanet follow-up community on several fronts by bringing previously unused instrument options to the endeavour, contributing to the general effort of candidate verification, as well as leading validation and confirmation studies of challenging long-period targets. We adapted the Dragonfly Telephoto Array (a.k.a. “Dragonfly”), designed for low-surface brightness targets, to the observation of exoplanet transits. I developed a new transient-appropriate observing mode and created scheduling, data processing, and analysis pipelines. We achieve a photometric precision floor of 0.5 ppt in 4–5-minute bins over the range 9 < mV < 13, competitive other 1–2 m class ground-based observatories. We also developed an extensive observing program with the Near-Earth Object Surveillance Satellite (NEOSSat) spanning 3 years and 6 observing cycles to observe long-duration exoplanet transits that provide a major challenge to capture with ground-based observatories. Using these two instruments, we provided follow-up observations for the TESS Exoplanet Follow-up Observing Program (ExoFOP). Through my work with ExoFOP, I led a validation publication for TOI-1221 b, a 2.9 Earth-radii sub-Neptune planet on a 92-day orbit. Not only do we rule out the false-positive scenarios for this long-period temperate planet, but through our detailed analysis of 6 TESS transits and 2 ground-based detections, we find evidence of transit timing variations that may indicate an additional hidden planet in the system. We also used NEOSSat to hunt for an elusive second transit of TOI-2010 b. By monitoring the host star over a 7-day uncertainty window, we caught the transit and vastly improved our knowledge of the planet’s ephemeris. I led the confirmation paper on this temperate Jupiter-like planet with a 142-day orbit, adding a low-insolation target to the small collection of known exoplanets with periods above 100 days and host stars bright enough for spectroscopic follow-up. Beyond leading these two specific projects, my observations with Dragonfly and NEOSSat have thus far contributed to 10 other publications for which I am co-author.

The present work deals with the development and application of an acoustic long-period fiber grating (LPG) in conjunction with a special optical fiber (SF). The acoustic LPG converts selected optical modes of the SF. Some of these modes are characterized by complex, yet cylindrically symmetric polarization and intensity patterns. Therefore, they are the guided variant of so called cylindrical vector beams (CVBs). CVBs find applications in numerous fields of fundamental and applied optics. Here, an application to high-resolution light microscopy is demonstrated. The field distribution in the tight microscope focus is controlled by the LPG, which in turn creates the necessary polarization and intensity distribution for the microscope illumination. A gold nanoparticle of 30 nm diameter is used to probe the focal field with sub-wavelength resolution. The construction and test of the acoustic LPG are discussed in detail. A key component is the piezoelectric transducer that excites flexural acoustic waves in the SF, which are the origin of an optical mode conversion. A mode conversion efficiency of 85% was realized at 785 nm optical wavelength. The efficiency is, at present, mainly limited by the spectral positions and widths of the transducer’s acoustic resonances. The SF used with the LPG separates the propagation constants of the second-order polarization modes, so they can be individually excited and are less sensitive to distortions than in standard weakly-guiding fibers. The influence of geometrical parameters of the fiber core on the propagation constant separation and on the mode fields is studied numerically using the multiple multipole method. From the simulations, a simple mode coupling scheme is developed that provides a qualitative understanding of the experimental results achieved with the LPG. The refractive index profile of the fiber core was originally developed by Ramachandran et al. However, an important step of the present work is to reduce the SF’s core size to counteract the the appearance of higher-order modes at shorter wavelengths which would otherwise spoil the mode purity. Using the acoustic LPG in combination with the SF produces a versatile device to generate CVBs and other phase structures beams. This fiber-optical method offers beam profiles of high quality and achieves good directional stability of the emitted beam. Moreover, the device design is simple and can be realized at low cost. Future developments of the acoustic LPG will aim at applications to fiber-optical sensors and optical near-field microscopy. / Diese Arbeit behandelt die Entwicklung und Anwendung eines akustischen langperiodischen Fasergitters (LPG) in Verbindung mit einer optischen Spezialfaser (SF). Das akustische LPG wandelt ausgewählte optische Modi der SF um. Einige dieser Modi weisen eine komplexe, zylindersymmetrische Polarisations- und Intensitätsverteilung auf. Diese sind eine Form der so genannten zylindrischen Vektor-Strahlen (CVBs), welche in zahlreichen Gebieten der wissenschaftlichen und angewandten Optik zum Einsatz kommen. In dieser Arbeit wird eine Anwendung auf die hochauflösende Lichtmikroskopie demonstriert. Die fokale Feldverteilung wird dabei durch die Auswahl der vom LPG erzeugten Modi, welche zur Beleuchtung genutzt werden, eingestellt. Als Nachweis wird die entstehende laterale Feldverteilung mithilfe eines Goldpartikels (Durchmesser 30 Nanometer) vermessen. Aufbau und Test des akustischen LPGs werden im Detail besprochen. Eine wichtige Komponente ist ein piezoelektrischer Wandler, der akustische Biegewellen in der SF anregt. Diese sind die Ursache der Umwandlung optischer Modi. Die maximale Konversionseffizienz betrug 85% bei 785 nm (optischer) Wellenlänge. Die Effizienz ist derzeit hauptsächlich durch die Lage der akustischen Resonanzfrequenzen des Wandlers und deren Bandbreite begrenzt. Die benutzte SF spaltet die Ausbreitungskonstanten von Polarisationsmodi zweiter Ordnung auf, sodass diese individuell angeregt werden können und weniger anfällig gegen über Störungen der Faser sind, als das bei gewöhnlichen, schwach führenden Glasfasern der Fall ist. Das zu Grunde liegende Brechzahlprofil des Faserkerns wurde von Ramachandran et al. entwickelt. Für diese Arbeit wurde jedoch die Ausdehnung des Profils verkleinert – ein erster Schritt um Anwendungen bei kürzeren optischen Wellenlängen zu ermöglichen. Es werden numerische Simulationen mit der Methode der multiplen Multipole zur Berechnung der Modenfelder und den zugehörigen Propagationskonstanten vorgestellt. Diese zeigen u. a. den starken Einfluss von geometrischen Veränderungen des Faserkerns. Basierend auf den Simulationsergebnissen wird ein einfaches Kopplungsschema für die Modi entwickelt, welches ein qualitatives Verständnis der experimentellen Ergebnisse ermöglicht. In Kombination bilden die SF und das LPG ein vielseitiges Gerät zur Erzeugung von CVBs und anderen Strahlen mit komplexer Phasenstruktur. Die Methode besticht durch hohe Qualität des Strahlprofils, stabile Abstrahlrichtung, einfachen Aufbau, elektronische Steuerbarkeit und geringe Materialkosten. Zukünftige Weiterentwicklungen des akustischen LPGs zielen auf die Anwendung in faseroptischen Sensoren und in der optischen Nahfeldmikroskopie ab.

[EN] Fiber grating sensors and devices have demonstrated outstanding capabilities in both telecommunications and sensing areas, due to their well-known advantageous characteristics. Therefore, one of the most important motivations lies in the potential of customized fiber gratings to be suitably employed for improving the interrogation process of optical fiber sensors and systems. This Ph.D. dissertation is focused on the study, design, fabrication and performance evaluation of customized fiber Bragg gratings (FBGs) and long period gratings (LPGs) with the double aim to present novel sensing technologies and to enhance the response of existing sensing systems. In this context, a technique based on time-frequency domain analysis has been studied and applied to interrogate different kind of FBGs-based sensors. The distribution of the central wavelength along the sensing structures has been demonstrated, based on a combination of frequency scanning of the interrogating optical pulse and optical time-domain reflectometry (OTDR), allowing the detection of spot events with good performance in terms of measurand resolution. Moreover, different customized FBGs have been interrogated using a technology inspired on the operation principle of microwave photonics (MWP) filters, enabling the detection of spot events using radio-frequency (RF) devices with modest bandwidth. The sensing capability of these technological platforms has been fruitfully employed for implementing a large scale quasi-distributed sensor, based on an array of cascaded FBGs. The potentiality of LPGs as fiber optic sensors has also been investigated in a new fashion, exploiting the potentials of MWP filtering techniques. Besides, a novel approach for simultaneous measurements based on a half-coated LPG has been proposed and demonstrated. Finally, the feasibility of FBGs as selective wavelength filters has been exploited in sensing applications; an alternative approach to improve the response and performance of Brillouin distributed fiber sensors has been studied and validated via experiments. The performance of the reported sensing platforms have been analyzed and evaluated so as to characterize their impact on the fiber sensing field and to ultimately identify the use of the most suitable technology depending on the processing task to be carried out and on the final goal to reach. / [ES] Los sensores y dispositivos en fibra basados en redes de difracción han mostrado excepcionales capacidades en el ámbito de las telecomunicaciones y del sensado, gracias a sus excelentes propiedades. Entre las motivaciones más estimulantes destaca la posibilidad de fabricar redes de difracción ad-hoc para implementar y/o mejorar las prestaciones de los sensores fotónicos. Esta tesis doctoral se ha enfocado en el estudio, diseño, fabricación y evaluación de las prestaciones de redes de difracción de Bragg (FBGs) y de redes de difracción de periodo largo (LPGs) personalizadas con el fin de desarrollar nuevas plataformas de detección y a la vez mejorar la respuesta y las prestaciones de los sensores fotónicos ya existentes. En este contexto, una técnica basada en el análisis tiempofrecuencia se ha estudiado e implementado para la interrogación de sensores en fibra basados en varios tipos y modelos de FBGs. Se ha analizado la distribución de la longitud de onda central a lo largo de la estructura de sensado, gracias a una metodología que conlleva el escaneo en frecuencia del pulso óptico incidente y la técnica conocida como reflectometria óptica en el dominio del tiempo (OTDR). De esta manera se ha llevado a cabo la detección de eventos puntuales, alcanzando muy buenas prestaciones en términos de resolución de la magnitud a medir. Además, se han interrogado varias FBGs a través de una técnica basada en el principio de operación de los filtros de fotónica de microondas (MWP), logrando así la detección de eventos puntuales usando dispositivos de radio-frecuencia (RF) caracterizados por un moderado ancho de banda. La capacidad de sensado de estas plataformas tecnológicas ha sido aprovechada para la realización de un sensor quasi-distribuido de gran alcance, formado por una estructura en cascada de muchas FBGs. Por otro lado, se han puesto a prueba las capacidades de las LPGs como sensores ópticos según un enfoque novedoso; para ello se han aprovechados las potencialidades de los filtros de MWP. Asimismo, se ha estudiado y demostrado un nuevo método para medidas simultáneas de dos parámetros, basado en una LPG parcialmente recubierta por una película polimérica. Finalmente, se ha explotado la viabilidad de las FBGs en cuanto al filtrado selectivo en longitud de onda para aplicaciones de sensado; para ello se ha propuesto un sistema alternativo para la mejora de la respuesta y de las prestaciones de sensores ópticos distribuidos basados en el scattering de Brillouin. En conclusión, se han analizado y evaluado las prestaciones de las plataformas de sensado propuestas para caracterizar su impacto en el ámbito de los sistemas de detección por fibra y además identificar el uso de la tecnología más adecuada dependiendo de la tarea a desarrollar y del objetivo a alcanzar. / [CA] Els sensors i dispositius en fibra basats en xarxes de difracció han mostrat excepcionals capacitats en l'àmbit de les telecomunicacions i del sensat, gràcies a les seus excel¿lents propietats. Entre les motivacions més estimulants destaca la possibilitat de fabricar xarxes de difracció ad-hoc per a implementar i/o millorar les prestacions de sensors fotònics. Esta tesi doctoral s'ha enfocat en l'estudi, disseny, fabricació i avaluació de les prestacions de xarxes de difracció de Bragg (FBGs) i de xarxes de difracció de període llarg (LPGs) personalitzades per tal de desenvolupar noves plataformes de detecció i al mateix temps millorar la resposta i les prestacions dels sensors fotònics ja existents. En este context, una tècnica basada en l'anàlisi temps-freqüència s'ha estudiat i implementat per a la interrogació de sensors en fibra basats en diversos tipus i models de FBGs. S'ha analitzat la distribució de la longitud d'ona central al llarg de l'estructura de sensat, gràcies a una metodologia que comporta l'escaneig en freqüència del pols òptic incident i la tècnica coneguda com reflectometria òptica en el domini del temps (OTDR). D'esta manera s'ha dut a terme la detecció d'esdeveniments puntuals, aconseguint molt bones prestacions en termes de resolució de la magnitud a mesurar. A més, s'han interrogat diverses FBGs a través d'una tècnica basada en el principi d'operació dels filtres de fotònica de microones (MWP), aconseguint així la detecció d'esdeveniments puntuals utilitzant dispositius de ràdio-freqüència (RF) caracteritzats per un moderat ample de banda. La capacitat de sensat d'aquestes plataformes tecnològiques ha sigut aprofitada per a la realització d'un sensor quasi-distribuït a llarga escala, format per una estructura en cascada de moltes FBGs. D'altra banda, s'han posat a prova les capacitats de les LPGs com a sensors òptics segons un enfocament nou; per a això s'han aprofitat les potencialitats dels filtres de MWP. Així mateix, s'ha estudiat i demostrat un nou mètode per a mesures simultànies de dos paràmetres, basat en una LPG parcialment recoberta per una pel¿lícula polimèrica. Finalment, s'ha explotat la viabilitat de les FBGs pel que fa al filtrat selectiu en longitud d'ona per a aplicacions de sensat; per això s'ha proposat un sistema alternatiu per a la millora de la resposta i de les prestacions de sensors òptics distribuïts basats en el scattering de Brillouin. S'han analitzat i avaluat les prestacions de les plataformes de sensat propostes per a caracteritzar el seu impacte en l'àmbit dels sistemes de detecció per fibra i a més identificar l'ús de la tecnologia més adequada depenent de la tasca a desenvolupar i de l'objectiu a assolir. / Ricchiuti, AL. (2016). Design and fabrication of customized fiber gratings to improve the interrogation of optical fiber sensors [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/66343 / TESIS / Premios Extraordinarios de tesis doctorales

The present work deals with the development and application of an acoustic long-period fiber grating (LPG) in conjunction with a special optical fiber (SF). The acoustic LPG converts selected optical modes of the SF. Some of these modes are characterized by complex, yet cylindrically symmetric polarization and intensity patterns. Therefore, they are the guided variant of so called cylindrical vector beams (CVBs). CVBs find applications in numerous fields of fundamental and applied optics. Here, an application to high-resolution light microscopy is demonstrated. The field distribution in the tight microscope focus is controlled by the LPG, which in turn creates the necessary polarization and intensity distribution for the microscope illumination. A gold nanoparticle of 30 nm diameter is used to probe the focal field with sub-wavelength resolution. The construction and test of the acoustic LPG are discussed in detail. A key component is the piezoelectric transducer that excites flexural acoustic waves in the SF, which are the origin of an optical mode conversion. A mode conversion efficiency of 85% was realized at 785 nm optical wavelength. The efficiency is, at present, mainly limited by the spectral positions and widths of the transducer’s acoustic resonances. The SF used with the LPG separates the propagation constants of the second-order polarization modes, so they can be individually excited and are less sensitive to distortions than in standard weakly-guiding fibers. The influence of geometrical parameters of the fiber core on the propagation constant separation and on the mode fields is studied numerically using the multiple multipole method. From the simulations, a simple mode coupling scheme is developed that provides a qualitative understanding of the experimental results achieved with the LPG. The refractive index profile of the fiber core was originally developed by Ramachandran et al. However, an important step of the present work is to reduce the SF’s core size to counteract the the appearance of higher-order modes at shorter wavelengths which would otherwise spoil the mode purity. Using the acoustic LPG in combination with the SF produces a versatile device to generate CVBs and other phase structures beams. This fiber-optical method offers beam profiles of high quality and achieves good directional stability of the emitted beam. Moreover, the device design is simple and can be realized at low cost. Future developments of the acoustic LPG will aim at applications to fiber-optical sensors and optical near-field microscopy.:Abstract / Kurzfassung iii Table of contents v 1 Introduction 1 2 Fundamentals of optical waveguides 5 2.1 Introduction 5 2.2 Maxwell’s equations and vector wave equations 5 2.3 Optical waveguides 7 2.3.1 Dielectric waveguides 7 2.3.2 Metallic waveguides 9 2.4 Numerical calculation of modes by the multiple multipole program 10 2.4.1 Representation of simulated mode fields 11 2.5 Overview of coupled mode theory 14 2.5.1 Coupled mode equations 14 2.5.2 Co-directional coupling 15 2.6 Summary and conclusions 16 3 Polarization control for fundamental and higher order modes 17 3.1 Introduction 17 3.2 Description of light polarization 18 3.2.1 Stokes parameters and the polarization ellipse 18 3.2.2 Polarization of light beams in free space 20 3.2.3 Polarization of light beams in optical fibers 21 3.3 Short overview of cylindrical vector beam generation 22 3.4 Excitation of cylindrical vector beams in optical fibers 27 3.4.1 Free-beam techniques 27 3.4.2 In-fiber techniques 29 3.5 Polarization control in optical fibers 30 3.5.1 Phase matching and the beat length 30 3.5.2 Polarization-maintaining single-mode fibers 32 3.5.3 Higher-order mode polarization-maintaining fibers 32 3.6 Summary and conclusions 34 4 Simulation of core-ring-fibers 36 4.1 Introduction 36 4.2 Model geometries for index-tailored optical fiber 37 4.2.1 Special fiber and fabrication 37 4.2.2 Elliptical core boundaries 39 4.2.3 Overview of the applied MMP Models 41 4.3 Simulation results for circular core geometry 43 4.3.1 Mode fields 43 4.3.2 Scaling of the core radii 43 4.3.3 Wavelength dependence 48 4.4 Simulation results for non-circular geometry 50 4.4.1 Mode fields 50 4.4.2 Effects of individual rotation angles 53 4.4.3 Wavelength dependence 56 4.5 Summary and conclusions 61 5 Long period fiber gratings 63 5.1 Introduction 63 5.2 Principle of long-period fiber gratings 64 5.2.1 Results from coupled mode theory 64 5.2.2 Types of long-period gratings 65 5.2.3 Properties of acoustic long-period fiber gratings 67 5.3 Acoustic long-period grating setup 68 5.3.1 Transducer 69 5.3.2 Mechanical coupling 72 5.3.3 Acoustic dispersion of an optical fiber 75 5.3.4 Optical setup 77 5.3.5 Comparison to other acoustic LPG geometries 81 5.4 Experimental results 82 5.4.1 Transmission spectra 82 5.4.2 Discussion of transmission results 88 5.4.3 Direct mode field observation 93 5.4.4 Discussion of mode field observations 97 5.4.5 Time behavior and grating amplitude modulation 99 5.5 Summary and conclusions 101 6 Application of higher order fiber modes for far-field microscopy 104 6.1 Introduction 104 6.2 Complex beams in high-resolution far-field microscopy 104 6.3 Theoretical considerations 106 6.4 Experimental details 111 6.5 Results 114 6.6 Discussion 118 6.7 Summary and conclusions 122 7 Summary and outlook 124 Acknowledgments 139 Publications related to this work 142 List of figures 144 List of tables 150 List of acronyms 151 / Diese Arbeit behandelt die Entwicklung und Anwendung eines akustischen langperiodischen Fasergitters (LPG) in Verbindung mit einer optischen Spezialfaser (SF). Das akustische LPG wandelt ausgewählte optische Modi der SF um. Einige dieser Modi weisen eine komplexe, zylindersymmetrische Polarisations- und Intensitätsverteilung auf. Diese sind eine Form der so genannten zylindrischen Vektor-Strahlen (CVBs), welche in zahlreichen Gebieten der wissenschaftlichen und angewandten Optik zum Einsatz kommen. In dieser Arbeit wird eine Anwendung auf die hochauflösende Lichtmikroskopie demonstriert. Die fokale Feldverteilung wird dabei durch die Auswahl der vom LPG erzeugten Modi, welche zur Beleuchtung genutzt werden, eingestellt. Als Nachweis wird die entstehende laterale Feldverteilung mithilfe eines Goldpartikels (Durchmesser 30 Nanometer) vermessen. Aufbau und Test des akustischen LPGs werden im Detail besprochen. Eine wichtige Komponente ist ein piezoelektrischer Wandler, der akustische Biegewellen in der SF anregt. Diese sind die Ursache der Umwandlung optischer Modi. Die maximale Konversionseffizienz betrug 85% bei 785 nm (optischer) Wellenlänge. Die Effizienz ist derzeit hauptsächlich durch die Lage der akustischen Resonanzfrequenzen des Wandlers und deren Bandbreite begrenzt. Die benutzte SF spaltet die Ausbreitungskonstanten von Polarisationsmodi zweiter Ordnung auf, sodass diese individuell angeregt werden können und weniger anfällig gegen über Störungen der Faser sind, als das bei gewöhnlichen, schwach führenden Glasfasern der Fall ist. Das zu Grunde liegende Brechzahlprofil des Faserkerns wurde von Ramachandran et al. entwickelt. Für diese Arbeit wurde jedoch die Ausdehnung des Profils verkleinert – ein erster Schritt um Anwendungen bei kürzeren optischen Wellenlängen zu ermöglichen. Es werden numerische Simulationen mit der Methode der multiplen Multipole zur Berechnung der Modenfelder und den zugehörigen Propagationskonstanten vorgestellt. Diese zeigen u. a. den starken Einfluss von geometrischen Veränderungen des Faserkerns. Basierend auf den Simulationsergebnissen wird ein einfaches Kopplungsschema für die Modi entwickelt, welches ein qualitatives Verständnis der experimentellen Ergebnisse ermöglicht. In Kombination bilden die SF und das LPG ein vielseitiges Gerät zur Erzeugung von CVBs und anderen Strahlen mit komplexer Phasenstruktur. Die Methode besticht durch hohe Qualität des Strahlprofils, stabile Abstrahlrichtung, einfachen Aufbau, elektronische Steuerbarkeit und geringe Materialkosten. Zukünftige Weiterentwicklungen des akustischen LPGs zielen auf die Anwendung in faseroptischen Sensoren und in der optischen Nahfeldmikroskopie ab.:Abstract / Kurzfassung iii Table of contents v 1 Introduction 1 2 Fundamentals of optical waveguides 5 2.1 Introduction 5 2.2 Maxwell’s equations and vector wave equations 5 2.3 Optical waveguides 7 2.3.1 Dielectric waveguides 7 2.3.2 Metallic waveguides 9 2.4 Numerical calculation of modes by the multiple multipole program 10 2.4.1 Representation of simulated mode fields 11 2.5 Overview of coupled mode theory 14 2.5.1 Coupled mode equations 14 2.5.2 Co-directional coupling 15 2.6 Summary and conclusions 16 3 Polarization control for fundamental and higher order modes 17 3.1 Introduction 17 3.2 Description of light polarization 18 3.2.1 Stokes parameters and the polarization ellipse 18 3.2.2 Polarization of light beams in free space 20 3.2.3 Polarization of light beams in optical fibers 21 3.3 Short overview of cylindrical vector beam generation 22 3.4 Excitation of cylindrical vector beams in optical fibers 27 3.4.1 Free-beam techniques 27 3.4.2 In-fiber techniques 29 3.5 Polarization control in optical fibers 30 3.5.1 Phase matching and the beat length 30 3.5.2 Polarization-maintaining single-mode fibers 32 3.5.3 Higher-order mode polarization-maintaining fibers 32 3.6 Summary and conclusions 34 4 Simulation of core-ring-fibers 36 4.1 Introduction 36 4.2 Model geometries for index-tailored optical fiber 37 4.2.1 Special fiber and fabrication 37 4.2.2 Elliptical core boundaries 39 4.2.3 Overview of the applied MMP Models 41 4.3 Simulation results for circular core geometry 43 4.3.1 Mode fields 43 4.3.2 Scaling of the core radii 43 4.3.3 Wavelength dependence 48 4.4 Simulation results for non-circular geometry 50 4.4.1 Mode fields 50 4.4.2 Effects of individual rotation angles 53 4.4.3 Wavelength dependence 56 4.5 Summary and conclusions 61 5 Long period fiber gratings 63 5.1 Introduction 63 5.2 Principle of long-period fiber gratings 64 5.2.1 Results from coupled mode theory 64 5.2.2 Types of long-period gratings 65 5.2.3 Properties of acoustic long-period fiber gratings 67 5.3 Acoustic long-period grating setup 68 5.3.1 Transducer 69 5.3.2 Mechanical coupling 72 5.3.3 Acoustic dispersion of an optical fiber 75 5.3.4 Optical setup 77 5.3.5 Comparison to other acoustic LPG geometries 81 5.4 Experimental results 82 5.4.1 Transmission spectra 82 5.4.2 Discussion of transmission results 88 5.4.3 Direct mode field observation 93 5.4.4 Discussion of mode field observations 97 5.4.5 Time behavior and grating amplitude modulation 99 5.5 Summary and conclusions 101 6 Application of higher order fiber modes for far-field microscopy 104 6.1 Introduction 104 6.2 Complex beams in high-resolution far-field microscopy 104 6.3 Theoretical considerations 106 6.4 Experimental details 111 6.5 Results 114 6.6 Discussion 118 6.7 Summary and conclusions 122 7 Summary and outlook 124 Acknowledgments 139 Publications related to this work 142 List of figures 144 List of tables 150 List of acronyms 151