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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

System design of programmable 4f phase modulation techniques for rapid intensity shaping: A conceptual comparison

Roth, Matthias, Heber, Jörg, Janschek, Klaus 29 August 2019 (has links)
The present study analyses three beam shaping approaches with respect to a light-efficient generation of i) patterns and ii) multiple spots by means of a generic optical 4f-setup. 4f approaches share the property that due to the one-to-one relationship between output intensity and input phase, the need for time-consuming, iterative calculation can be avoided. The resulting low computational complexity offers a particular advantage compared to the widely used holographic principles and makes them potential candidates for real-time applications. The increasing availability of high-speed phase modulators, e.g. on the basis of MEMS, calls for an evaluation of the performances of these concepts. Our second interest is the applicability of 4f methods to high-power applications. We discuss the variants of 4f intensity shaping by phase modulation from a system-level point of view which requires the consideration of application relevant boundary conditions. The discussion includes i) the micro mirror based phase manipulation combined with amplitude masking in the Fourier plane, ii) the Generalized Phase Contrast, and iii) matched phase-only correlation filtering combined with GPC. The conceptual comparison relies on comparative figures of merit for energy efficiency, pattern homogeneity, pattern image quality, maximum output intensity and flexibility with respect to the displayable pattern. Numerical simulations illustrate our findings.
42

Advanced wavefront sensing and astrometric techniques for the next generation of extremely large telescopes

Taheri, Mojtaba 29 April 2022 (has links)
The new generation of giant ground-based telescopes will see their first light this decade. These state-of-the-art facilities will significantly surpass the resolving power of modern space-based observatories such as the James Webb telescope, thanks to their enormous aperture size and adaptive optics (AO) facilities. Without AO, atmospheric turbulence would degrade the image quality of these enormous telescopes to that of a 50 cm amateur one. These extremely large telescopes (ELTs) will further benefit from a particular branch of AO called multi-conjugate adaptive optics (MCAO), which provides an extremely high resolving power over a much wider field of view as compared to classical AO systems. The design and fabrication of such systems, as well as their optimal use for science operation, pose a great challenge as they are an order of magnitude more complicated than current AO systems. To face such a challenge, the combined knowledge of MCAO system design and fabrication, working in tandem with scientific insights into new astronomy science cases, is an extremely valuable and essential pairing. This thesis is an effort to not only contribute to the design and fabrication of ELT MCAO facilities, but also provide guidance on the optimal method to utilize these giant telescopes to achieve unprecedented astrometric measurements. On the instrumentation side, in partnership with the National Research Council of Canada's - Herzberg Astronomy and Astrophysics Institute as well as W.M. Keck Observatory in Hawaii, I was involved in the design and fabrication of a cutting edge new wavefront sensor, which is the eye of an AO system. I performed opto-mechanical design and verification studies for components of the Keck infrared pyramid wavefront sensor (IR-PWFS) as well as the Keck Planet Imager and characterizer (KPIC) instrument, which have both been commissioned and are in science operation. Furthermore, I designed the alignment plan and participated in the modification and alignment operation of a few components on the Keck II adaptive optics bench on the summit of Mauna Kea. To pave the way for the design verification of future MCAO systems for ELTs, I proposed a new method for an old challenge in the path of AO system design and verification: a flexible method for precise intensity pattern injection into laboratory AO benches. AO benches are the backbone of instrument design and modeling. One of the challenges especially important for the future generation of MCAO systems for ELTs is the verification of the effect of shadowed regions on the primary mirror. During my PhD, I successfully demonstrated the feasibility of a new proposed method to accurately model the telescope pupil. This work was done in partnership with the Laboratoire d'Astrophysique de Marseille (LAM) in France. The method I developed at LAM will be implemented in the AO Lab at NRC Herzberg Astronomy and Astrophysics. As an observational astronomer, I focused on developing methods for making optimal astrometric measurements with MCAO-enabled telescopes. The expected unparalleled astrometric precision of ELTs comes with many unprecedented challenges that if left unresolved, would jeopardize the success of these facilities as they would not be able to reach their science goals. I used observations with the only available MCAO system in science operation, the Gemini MCAO system on the 8-meter Gemini South telescope in Chile, to develop and verify a pipeline specifically designed for very high-precision astrometric studies with MCAO-fed imagers. I successfully used the pipeline to provide the precise on-sky differential distortion of the Gemini South telescope and its MCAO facilities by looking deep into the core of globular cluster NGC~6723. Using this pipeline, I produced high quality proper motions with an uncertainty floor of $\sim 45$\,$\mu$as~yr$^{-1}$ as well as measured the proper motion dispersion profile of NGC~6723 from a radius of $\sim 10$ arcseconds out to $\sim 1$\,arcminute, based on $\sim 12000$ stars. I also produced a high-quality optical-near-infrared color magnitude diagram which clearly shows the extreme horizontal branch and main-sequence knee of this cluster. / Graduate
43

Rydberg excitation dynamics and correlations in arbitrary 2D arrays of single atoms / La dynamique et correlations d'excitations Rydberg dans des matrices 2D des atomes unique

Labuhn, Henning 26 February 2016 (has links)
Dans cette thèse, nous mesurons la dynamique cohérente et les corrélations spatiales des excitations Rydberg dans des matrices 2D d’atomes uniques.Nous utilisons un modulateur spatial de lumière pour façonner la phase spatiale d'un faisceau laser de piégeage optique avant de le focaliser avec une lentille asphérique de grande ouverture numérique. En imprimant une phase appropriée sur le faisceau laser, nous pouvons créer des matrices 2D de pièges optiques, de forme arbitraire et facilement reconfigurables, avec jusqu'à 100 pièges séparées de quelques micromètres. Les pièges sont chargés à partir d'un nuage d'atomes froids de 87Rb, et due aux collisions assistées par la lumière, au plus un seul atome peut être présent dans chaque piège en même temps. Une caméra CCD sensible permet en temps réel l'imagerie de la fluorescence atomique émanant des pièges, ce qui nous permet de détecter individuellement la présence d'un atome dans chaque piège avec une précision presque parfaite.Pour créer des interactions importantes entre les atomes uniques, nous les excitons vers des états de Rydberg, qui sont des états électroniques avec un nombre quantique principal élevé.Un faisceau supplémentaire d'adressage permet la manipulation individuelle d'un atome sélectionné dans la matrice.La connaissance précise, de la fois de la matrice des atomes préparé et des positions des excitations Rydberg, nous a permis de mesurer l’augmentation collective de la couplage optique dans le régime de blocage Rydberg, où une seule excitation est partagée de façon symétrique entre tous les atomes de la matrice.Dans le régime où l'interaction ne s’étend que sur quelques sites, nous avons mesuré la dynamique et les corrélations spatiales des excitations Rydberg, dans des matrices d’atomes à une et deux dimensions. La comparaison à une simulation numérique d'un modèle d'Ising quantique d'un système de spin-1/2 montre un accord exceptionnel pour les matrices où l'effet de l'anisotropie de l’interaction Rydberg-Rydberg est faible. Les résultats obtenus démontrent que les atomes Rydberg uniques sont une plate-forme bien adaptée pour la simulation quantique des systèmes de spin. / In this thesis, we measure the coherent dynamics and the pair correlations of Rydberg excitations in two-dimensional arrays of single atoms.We use a spatial light modulator to shape the spatial phase of a single optical dipole trap beam before focusing it with a high numerical-aperture aspheric lens. By imprinting an appropriate phase pattern on the trap beam, we can create arbitrarily shaped and easily reconfigurable 2D arrays of high-quality single-atom traps, with trap-spacings of a few micrometers for up to 100 traps. The traps are loaded from a cloud of cold 87Rb atoms, and due to fast light-assisted collisions of atoms inside the traps, at most one atom can be present in each trap at the same time. A sensitive CCD camera allows the real-time, site-resolved imaging of the atomic fluorescence from the traps, enabling us to detect the presence of an atom in each individual trap with almost perfect accuracy.In order to induce strong, tunable interactions between the atoms in the array, we coherently laser-excite them to Rydberg states, which are electronic states with a high principal quantum number.An additional addressing beam allows the individual manipulation of an atom at a selected site in the array.The precise knowledge of both the prepared atom array and the positions of the Rydberg excitations allowed us to measure the collective enhancement of the optical coupling strength in the regime of full Rydberg blockade, where one single excitation is shared symmetrically among all atoms in the array.In the regime where the strong interaction only extends over a few sites, we measured the dynamics and the spatial pair-correlations of Rydberg excitations, in one- and two-dimensional atom arrays. The comparison to a numerical simulation of a quantum Ising model of a spin-1/2 system shows an exceptional agreement for trap geometries where the effect of the anisotropy of the Rydberg-Rydberg interaction is small. The obtained results demonstrate that single Rydberg atoms are a suitable platform for the quantum simulation of spin systems.
44

Optical eigenmodes for illumination & imaging

Kosmeier, Sebastian January 2013 (has links)
This thesis exploits so called “Optical Eigenmodes” (OEi) in the focal plane of an optical system. The concept of OEi is introduced and the OEi operator approach is outlined, for which quadratic measures of the light field are expressed as real eigenvalues of an Hermitian operator. As an example, the latter is employed to locally minimise the width of a focal spot. The limitations of implementing these spots with state of the art spatial beam shaping technique are explored and a selected spot with a by 40 % decreased core width is used to confocally scan an in focus pair of holes, delivering a two-point resolution enhanced by a factor of 1.3. As a second application, OEi are utilised for fullfield imaging. Therefore they are projected onto an object and for each mode a complex coupling coefficient describing the light-sample interaction is determined. The superposition of the OEi weighted with these coefficients delivers an image of the object. Compared to a point-by-point scan of the sample with the same number of probes, i.e. scanning points, the OEi image features higher spatial resolution and localisation of object features, rendering OEi imaging a compressive imaging modality. With respect to a raster scan a compression by a factor four is achieved. Compared to ghost imaging as another fullfield imaging method, 2-3 orders of magnitude less probes are required to obtain similar images. The application of OEi for imaging in transmission as well as for fluorescence and (surface enhanced) Raman spectroscopy is demonstrated. Finally, the applicability of the OEi concept for the coherent control of nanostructures is shown. For this, OEi are generated with respect to elements on a nanostructure, such as nanoantennas or nanopads. The OEi can be superimposed in order to generate an illumination of choice, for example to address one or multiple nanoelements with a defined intensity. It is shown that, compared to addressing such elements just with a focussed beam, the OEi concept reduces illumination crosstalk in addressing individual nanoelements by up to 70 %. Furthermore, a fullfield aberration correction is inherent to experimentally determined OEi, hence enabling addressing of nanoelements through turbid media.
45

Optique adaptative par modulateur spatial de lumière en microscopie et holographie / Adaptative optics with spatial light modulator for microscopy and holography

Gemayel, Pierre 18 February 2016 (has links)
Depuis les années 50, la récupération de la phase d’un faisceau optique diffracté par un objet quelconque, est un sujet important dans plusieurs domaines scientifiques, comme la microscopie, l’astronomie et bien d’autres. Généralement, les méthodes qui le permettent se divisent en deux grandes catégories : les méthodes interférométriques et les méthodes itératives basées sur la propagation du faisceau. L’intérêt de ces dernières, réside dans le fait qu’elles sont moins sensibles au bruit, et leur implémentation expérimentale est plus simple. Aussi, le développement des techniques informatiques a rendu cette approche plus rapide et plus intéressante. Cependant, même si l’efficacité de ces méthodes a été démontrée dans plusieurs domaines, leur utilisation est restée limitée à cause de certaines exigences sur les conditions expérimentales, et à la non-convergence de leur algorithme vers une solution unique dans un grand nombre de cas. Ceci est encore plus vrai pour les objets dits "objets complexes", possédant une amplitude et une phase, ce qui réduit fortement leur champ d’application. Afin de surmonter ces problèmes de convergence, diverses stratégies expérimentales ont été développées. Elles ont toutes comme principe d’introduire de nouvelles contraintes bien connues dans le plan de l’objet. Cela permet d’augmenter le nombre de spectres acquis, et donc accroitre et diversifier les sources d’informations sur l’objet de base, ce qui va aider l’algorithme itératif à converger plus rapidement vers une solution finale et unique. Comme exemple de ces stratégies expérimentales, on peut acquérir plusieurs spectres provenant de différentes zones de l’objet, ou moduler la longueur d’onde du faisceau incident, ou même enregistrer les spectres dans des plans parallèles, connectés entre eux par la transformée de Fresnel. Dans ce contexte, le présent travail vise à démontrer expérimentalement une technique connue sous SSPR (Spread Spectrum Phase Retrieval), proposé en 2007 par Zhang, tout en lui introduisant un certain nombre de modifications, afin de la rendre plus pratique. L’idée consiste à moduler le front d’onde de l’objet par M phases aléatoires, générées avec un modulateur spatial de lumière à base de cristaux liquides (LC-SLM), puis enregistrer dans le plan de Fourier les M spectres correspondants. Ces M spectres seront ensuite utilisés dans un algorithme itératif permettant de remonter au front d’onde de l’objet initial, en simulant la propagation du front d’onde entre les deux espaces, spatial et fréquentiel.La première partie de cette thèse comporte une étude détaillée sur les modulateurs spatiaux de lumière, afin de pouvoir choisir le mieux adapté à notre application. Une fois que le modulateur à base de cristaux liquides (LC-SLM) est sélectionné, on présentera ses caractéristiques techniques, ainsi que les tests et les étapes de calibrations nécessaires pour assurer son fonctionnement linéaire et optimal. Ensuite, on montrera plusieurs types d’applications possibles avec ce composant, et dans divers domaines scientifiques, comme l’holographie, la microscopie, l’optique adaptative ainsi que les méthodes interférométriques permettant de reconstruire la phase d’un faisceau lumineux. Dans la deuxième grande partie, on concentre notre travail autour de la méthode itérative SSPR. On montrera comment on peut rendre l’application de cette méthode plus simple en utilisant un modulateur spatial de lumière à base de cristaux liquides, et en travaillant dans le plan de Fourier à la place du plan de Fresnel. Cependant, après avoir appliqué expérimentalement cette méthode, on remarque que les résultats obtenus sont très mauvais par rapport aux résultats des simulations. On effectue donc, une étude détaillée concernant les sources de bruits pouvant être responsable de la dégradation de la qualité des reconstructions obtenues. [...] / Since the 50s, recovering the phase information of a diffracted beam has a major interest in several fields such as microscopy, astronomy and many others. Generally, the solutions fall into two broad categories: interferometric methods and iterative methods based on beam propagation. The advantage of the latter is that they are less sensitive to noise, and their experimental implementation is simpler. Also, the progress in computer technologies as well in digital imaging devices makes the application of this approach easier and more interesting. However, even if the effectiveness of these methods has been demonstrated in several fields, their use remained limited because of certain requirements on the experimental conditions and the non-convergence of their algorithm to a single solution in many cases. This is even more true for the so-called "complex objects", having an amplitude and a phase, which can greatly reduce their field of application. To overcome the convergence problems and improve the robustness of these methods, many experimental strategies have been employed. They are all based on the same principle, which consists of introducing new well-known constraints in the object plane. This increases the number of acquired spectrum, and therefore diversifies the sources of information about the starting object, which will help the iterative algorithm to converge more quickly towards the final solution. As examples of such experimental strategies, one can record several spectra from different areas of the object, or modulate the wavelength of the incident beam, or also acquire the spectrums across two or more parallel planes connected through Fresnel or Fourier transform.In this context, the present work aims to experimentally demonstrate a technique known as SSPR (Spread Spectrum Phase Retrieval), proposed in 2007 by Zhang, while modifying it in order to make it more flexible. The idea is to introduce, using a liquid crystal spatial light modulator M strong phase modulation into the object field, then record in the Fourier plane the M corresponding spectrums. These M acquisitions will then be used in an iterative algorithm what will allow us to recover the object wavefront by simulating the propagation of the light between spatial and frequency spaces. The first part of this thesis includes a complete study on spatial light modulators; in order to select which one will be best suited for our application. Once liquid crystal spatial light modulators are selected, we present their technical characteristics, as well as the calibration tests needed to ensure their linear and optimal functioning. Then we show several possible applications with this type of component, in various scientific fields, like holography, microscopy, adaptive optics and interferometric methods to reconstruct the phase of a beam.In the second part, we focus our work around the SSPR iterative method. We will show how to make the application of this method simpler by using a liquid crystal spatial light modulator, and by working in Fourier plane instead of Fresnel plane. However, after applying SSPR we have noticed that the quality of experimental results is very inferior to the quality of simulation results. Therefore, a detailed study of the noise sources is conducted. Each of these noise sources adds its own contribution, yet modulator cross-talk remains the factor that deteriorates the most the quality of reconstruction. In fact liquid crystal spatial light modulators are known to have a strong cross-talk between their pixels commonly recognized as fringing field effect. As the pixels are micrometric, each addressed one affects its neighbors, and thus, the phase retardation obtained from a pixel will not be uniform over its entire surface. This will result in a blurring effect of the desired sharp edge between the pixels; therefore, the real displayed phase map will be very different from the addressed one. [...]
46

Spectroscopie à corrélation de fluorescence multi-confocale : développement et application à l'étude de la réponse cellulaire au choc thermique / Multi-confocal fluorescence correlation spectroscopy and its application to the study of the cellular response to heat shock

Kloster-Landsberg, Meike 01 October 2012 (has links)
Le noyau d'une cellule est hétérogène par sa structure et son activité et beaucoup de ses composants interagissent de façon dynamique. Lors de l'étude de processus cellulaires comme la réponse au stress thermique, des expériences classiques de spectroscopie de corrélation de fluorescence (FCS), qui sont habituellement limitées à un seul volume d'observation, n'apportent que des résultats partiels à cause des informations spatiales manquantes. Ce mémoire de thèse présente une nouvelle technique de FCS multi-confocale (mFCS) qui permet des mesures FCS simultanées à différents endroits d'une cellule. La technique est basée sur l'emploi d'un modulateur spatial de lumière pour la création de plusieurs volumes d'observations distincts et d'une caméra ``electron-multiplying'' CCD (EMCCD) pour la détection en parallèle. La résolution spatiale ainsi que la sensibilité du système mFCS sont proches de celles d'un système FCS classique et en utilisant un mode d'acquisition particulier une résolution temporelle de $14mu s$ a pu être atteinte. La technique mFCS est appliquée à l'étude de la réponse cellulaire au stress thermique en observant le facteur de transcription heat shock factor 1 (HSF1), qui est un régulateur clé de la réponse au stress thermique. Des mesures mFCS dans des cellules vivantes révèlent des changements dans la dynamique de HSF1 pendant le choc thermique. Ces changements concernent l'affinité ainsi que l'homogénéité spatiale des interactions avec l'ADN. En outre, nous avons également évalué les performances d'une caméra CMOS-SPAD et testé le dispositif en tant que capteur alternatif pour la mFCS en cellules vivantes. / The cell nucleus is heterogeneous in its structure and activity and many of its components are in dynamic interactions with each other. When investigating the cellular response to an external signal, such as heat shock, standard fluorescence correlation spectroscopy (FCS) experiments, which are limited to one observation volume, do only give partial results because of the missing spatial information. This work introduces a novel multi-confocal FCS (mFCS) technique that allows simultaneous FCS measurements in different locations within a cell. It is based on the use of a spatial light modulator (SLM) to create several distinct observation volumes at a time and an electron-multiplying charge coupled device (EMCCD) camera to perform parallel detection. The spatial resolution as well as the sensibility of the mFCS system are close to that of a classical FCS setup and using a special readout mode, a temporal resolution of $14mu s$ is reached. The mFCS technique is applied to study the cellular response to thermal stress by monitoring the transcription factor heat shock factor 1 (HSF1), which is a key regulator of the heat shock response. mFCS experiments in living cells reveal changes in the dynamics of HSF1 upon heat shock. These changes concern the affinity as well as the spatial homogeneity of its interactions with DNA. Additionally, the performance of a CMOS-SPAD camera, consisting of an array of single photon avalanche diodes, is evaluated and the device is tested as an alternative detector for mFCS in living cells.
47

Evaluating and Correcting 3D Flash LiDAR Imagers

Reinhardt, Andrew David 09 August 2021 (has links)
No description available.
48

Combinaison cohérente dans une fibre multicœurs pour des applications LIDAR / Coherent combining in multicore fiber for LIDAR applications

Prevost, Florian 28 February 2017 (has links)
Les Lidars cohérents permettent de mesurer la vitesse du vent à grande distance, en se basant sur le décalage en fréquence Doppler induit par la réflexion des aérosols. Le Lidar vent est composé d'un système MOPFA (Master Oscillator Power Fiber Amplifier), contenant un oscillateur continu, un modulateur d'intensité, et un amplificateur fibré. L'objectif principal de cette thèse est la réalisation d'un MOPFA pulsé de forte puissance crête à sécurité oculaire, en utilisant une fibre multicoeurs dopée erbium. L'impulsion mono-fréquence dans les fibres est limitée par les effets non-linéaire du au confinement du faisceau dans le coeur. Les fibres multicoeurs peuvent être vues comme des fibres à larges coeur. L'impulsion à amplifier est divisée et injectée dans tous les coeurs de la fibre amplificatrice à l'aide d'un modulateur spatial de lumière (SLM). A la sortie, les impulsions amplifiées sont recombinées par un élément optique de diffraction (EOD). La combinaison cohérente en sortie requière un contrôle indépendant des phases à l'injection qui est asservit par un algorithme basé sur la puissance de l'ordre zéro de l'EOD. La puissance crête après combinaison est alors la somme des puissances crêtes atteintes dans chacun des coeurs. / Coherent Lidars can measure wind speed at long distance, using the Doppler frequency shift induced by the movement of the back reflecting aerosols. Wind Lidars usually include a MOPFA (Master Oscillator Power Fiber Amplifier) made of a continuous oscillator, an intensity modulator and a fiber amplifier. The main objective of this thesis is the realization of an eye-safe, high peak power, pulsed MOPFA using an erbium-doped multicore fiber. Single frequency pulse amplification in fibers is limited by nonlinear effects due to tight beam confinement in the core. Multicore fibers can be seen as a very large core fiber, thus mitigating the nonlinear effects. The pulse to be amplified is divided and injected into all cores of the amplifying fiber using a spatial light modulator (SLM). The amplified output pulses are then recombined at the fiber output by a diffractive optical element (DOE). The coherent combination at fiber output requires independent control of phases at injection provided by a feedback loop based on the DOE zero order power. The peak power after combination is the sum of the peak powers reached in each of the cores.
49

Studies of particle and atom manipulation using free space light beams and photonic crystal fibres

Gherardi, David Mark January 2009 (has links)
Light can exert optical forces on matter. In the macroscopic world these forces are minuscule, but on the microscopic or atomic scale, these forces are large enough to trap and manipulate particles. They may even be used to cool atoms to a fraction of a degree above absolute zero. This thesis details a number of experiments concerned with the optical manipulation of atoms and micron-size particles using free space light beams and photonic crystal fibres. Two atom guiding experiments are described. In the first experiment, a spatial light modulator is used to generate higher blue-detuned azimuthal Laguerre-Gaussian LG) beams, which are annular beams with a hollow core. These LG beams are then used to guide laser cooled rubidium-85 atoms within the dark core over a distance of 30 mm. The second atom guiding experiment involves attempting to guide laser cooled and thermal rubidium atoms through a hollow-core photonic crystal fibre using red-detuned light. Hollow-core photonic crystal fibres are fibres that are able to guide light with low attenuation within a hollow core. For this experiment a hot wire detection system was designed, along with a number of complex vacuum systems. The first dual-beam fibre trap for micron-size particles constructed using endlessly single-mode photonic crystal fibre (ESM-PCF) is described. The characteristics of dual-beam fibre traps are governed by the fibres used. As ESM-PCF has considerably different properties in comparison to conventional single- or multimode fibres, this dual beam ESM-PCF trap exhibits some novel characteristics. I show that the dual beam ESM-PCF trap can form trapping, repulsive and line potentials; an interference-free ‘white light’ trap; and a dual-wavelength optical conveyor belt.
50

Programmable ultrashort highly localized wave packets

Bock, Martin 01 October 2013 (has links)
Die vorliegende Arbeit beschäftigt sich mit dem Konzept der radial nicht-oszillierenden, zeitlich stabilen ultrakurzen Bessel ähnlichen Strahlen oder "Nadelstrahlen" ("needle beams"), die zu einer Klasse von optischen hochlokalisierten Wellenpaketen generalisiert werden. Hierbei wird die Theorie über das räumlich-zeitlichen Ausbreitungsverhaltens von nicht auseinanderdriftenden Nadelstrahlen mit Pulsdauern von kleiner als 10 fs näher diskutiert. Dies wird durch eine systematische Darstellung der Methoden zur Generierung und Detektierung von lokalisierten Wellen komplettiert, die ein optischen Drehmoment tragen. Für die Erzeugung von HLWs kommen räumliche Lichtmodulatoren zum Einsatz, die ein flexibles Zuschneiden von Wellenpaketen mit der Dauer weniger Zyklen des EM-Feldes erlauben. Es wird gezeigt, dass solche optischen Pulse sich über beträchtliche Entfernungen ausbreiten, ohne dass sich dabei signifikant der Strahldurchmesser vergrößert oder der Puls zeitlich verbreitert. In variabler Weise werden verschiedene geometrische (z.B. ringförmige) Lichtverteilungen erzeugt. Anwendungspotential findet sich insbesondere in den Techniken der räumlichen Pulsformung und Diagnostik. Als besonders wichtiger Ansatz ist der Zeit-Wellenfront-Sensor zu erwähnen, welcher die nichtlineare, mehrkanalige Autokorrelation, die Wellenfrontdetektion mittels nichtdiffraktiver Teilstrahlen nach dem Shack-Hartmann-Prinzip und eine adaptive Funktionalität miteinander vorteilhaft verbindet. Das enorme Potential solcher Ansätze wird durch die hohe Genauigkeit orts-, winkel- und zeitabhängiger Rekonstruktionen der Wellenpakete nachgewiesen. Darüber hinaus ermöglicht das räumliche Kodieren und anschließende Verfolgen der Teilstrahlen eine wesentliche Verbesserung der Identifikation relevanter Parameter von Verteilungsfunktionen. Schließlich werden erste Schritte zur experimentellen Generation von optischen "light bullets" mit ganzzahligen und fraktalen orbitalen Drehmomenten präsentiert. / This thesis deals with the concept of radially non-oscillating, temporally stable ultrashort-pulsed Bessel-like beams or "needle pulses", which are an example of a highly localized wave packet (HLW). HLWs are the closest approximation of linear-optical light bullets and provide specific benefits compared to conventional Gaussian-like light bullets. The spatio-temporally nonspreading propagation behavior of few-cycle needle beams of less than 10 fs duration will be theoretically discussed in detail. An overview of the generation and detection of localized waves carrying an orbital angular momentum is also given. High fidelity spatial light modulators are used for the generation of HLWs. The flexible tailoring of few-cycle wave packets at near-infrared wavelengths is reported. It is shown that such pulses propagate over a huge depth of focus, neither significantly changing their spot size or nor the pulse duration. Variable geometrical distributions like circular disks, rings, or bars of light are shaped and exploited as building blocks for structures of higher complexity. Another section of the thesis emphasizes the numerous potential applications of related techniques for an optimized two-dimensional spatial pulse shaping and diagnostics (reduce ambiguities) based on localized waves. As a particularly important example, time-wavefront sensing is used to combine nonlinear multichannel autocorrelation with Shack-Hartmann wavefront sensing by means of localized sub-beams and adaptive functionality. The capabilities of such devices are illustrated by the results of angular and temporal mapping of few-cycle wave packets. Moreover, spatial encoding and subsequent tracking of individual sub-beams, even at incident angles of up to 50°, enables to significantly improve the spot recognition. Finally, first steps towards the generation of optical light bullets carrying integer or non-integer orbital angular momenta are presented.

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