Dissertations / Theses on the topic 'Optical guiding'

Savoir différiencier les différentes types de tissus représente un aspect important lors d’interventions médicales, que ce soit pour aider au diagnostic d’une maladie ou pour le guidage chirurgical. Il est généralement très difficile de distinguer les tissus sains des tissus pathologiques à l’oeil nu et la navigation chirurgicale peut parfois être difficile dans les grands organes où la structure ciblé se trouve enfouie profondément. De nouvelles méthodes susceptibles d’accroître la réussite de telles interventions médicales suscitent actuellement de l’intérêt chez les professionnels de la santé. La spectroscopie optique, en analysant les interactions lumière-tissu dans une plage spectrale définie, est un outil permettant de différencier les tissus avec une résolution et une sensibilité bien supérieures à celles de l’oeil humain. Tout au long de cette thèse, je détaillerai comment la spectroscopie optique a été utilisée pour créer et améliorer un système de guidage optique utilisé pour la stimulation cérébrale profonde en neurochirurgie, en particulier pour le traitement de la maladie de Parkinson. Pour commencer, je montrerai comment les informations spectroscopiques peuvent fournir une rétroaction peropératoire en temps réel à un neurochirurgien, au cours de la phase d’implantation de la procédure, avec une sonde qui n’induit aucune invasion supplémentaire. Je présenterai l’investigation de deux modalités spectroscopiques différentes pour la discrimination tissulaire pour le guidage, soit la spectroscopie à réflectance diffuse et la spectroscopie de diffusion Raman anti-Stokes cohérente. Les avantages et les inconvénients des deux techniques, ainsi que leurs aptitude à la traduction prometteuse pour cette application seront abordés. Par la suite, je présenterai une nouvelle technique d’analyse de données pour extraire l’oxygénation des tissus à partir de spectres de réflectance diffus dans le but d’améliorer la précision de mesure en spectroscopie rétinienne et ultimement de porter un diagnostique. Bien que conçu pour la rétine, l’algorithme peut également être utilisé pour analyser les spectres acquis lors d’une neurochirurgie afin de fournir des informations à la fois discriminantes et diagnostiques. Finalement, je montrerai des preuves de diffusion anisotrope de la lumière dans les axones myélinisés de la moelle épinière et discuterai des conséquences que cela pourrait avoir sur les simulations actuelles de la propagation des photons dans le cerveau, qui feront partie intégrante d’un guidage optique efficace.
Savoir différiencier les différentes types de tissus représente un aspect important lors d’interventions médicales, que ce soit pour aider au diagnostic d’une maladie ou pour le guidage chirurgical. Il est généralement très difficile de distinguer les tissus sains des tissus pathologiques à l’oeil nu et la navigation chirurgicale peut parfois être difficile dans les grands organes où la structure ciblé se trouve enfouie profondément. De nouvelles méthodes susceptibles d’accroître la réussite de telles interventions médicales suscitent actuellement de l’intérêt chez les professionnels de la santé. La spectroscopie optique, en analysant les interactions lumière-tissu dans une plage spectrale définie, est un outil permettant de différencier les tissus avec une résolution et une sensibilité bien supérieures à celles de l’oeil humain. Tout au long de cette thèse, je détaillerai comment la spectroscopie optique a été utilisée pour créer et améliorer un système de guidage optique utilisé pour la stimulation cérébrale profonde en neurochirurgie, en particulier pour le traitement de la maladie de Parkinson. Pour commencer, je montrerai comment les informations spectroscopiques peuvent fournir une rétroaction peropératoire en temps réel à un neurochirurgien, au cours de la phase d’implantation de la procédure, avec une sonde qui n’induit aucune invasion supplémentaire. Je présenterai l’investigation de deux modalités spectroscopiques différentes pour la discrimination tissulaire pour le guidage, soit la spectroscopie à réflectance diffuse et la spectroscopie de diffusion Raman anti-Stokes cohérente. Les avantages et les inconvénients des deux techniques, ainsi que leurs aptitude à la traduction prometteuse pour cette application seront abordés. Par la suite, je présenterai une nouvelle technique d’analyse de données pour extraire l’oxygénation des tissus à partir de spectres de réflectance diffus dans le but d’améliorer la précision de mesure en spectroscopie rétinienne et ultimement de porter un diagnostique. Bien que conçu pour la rétine, l’algorithme peut également être utilisé pour analyser les spectres acquis lors d’une neurochirurgie afin de fournir des informations à la fois discriminantes et diagnostiques. Finalement, je montrerai des preuves de diffusion anisotrope de la lumière dans les axones myélinisés de la moelle épinière et discuterai des conséquences que cela pourrait avoir sur les simulations actuelles de la propagation des photons dans le cerveau, qui feront partie intégrante d’un guidage optique efficace.
Differentiating tissue types is an important aspect of guiding medical interventions whether it be for disease diagnosis or for surgical guidance. However, diseased and healthy tissues are often hard to discriminate by human vision alone and surgical navigation can be difficult to accomplish in large organs where the target structure lies deep within the body. New methods that can increase certainty in such medical interventions are therefore of great interest to healthcare professionals. Optical spectroscopy is a tool which can be exploited to probe discriminatory information in tissue by analyzing light-tissue interactions with a spectral range, resolution and sensitivity much greater than the human eye. Throughout this thesis, I will explain how I have leveraged optical spectroscopy to create, and improve, an optical guidance system for deep brain stimulation neurosurgery, specifically for the treatment of Parkinson’s disease. I will begin by describing how spectroscopic information can provide real-time feedback to a surgeon during the procedure, in the hopes of ultimately improving treatment outcome. To this end, I will present the investigation of two different spectroscopic modalities for optical guidance: diffuse reflectance spectroscopy, and coherent anti-Stokes Raman scattering spectroscopy. The advantages and disadvantages of both techniques will be discussed along with their promising translatability for this application. Following this, I will present a novel data analysis technique for extracting the tissue oxygenation from diffuse reflectance spectra with the aim of improved diagnostic information in retinal spectroscopy. While designed for the retina, the algorithm can also be used to analyze spectra acquired during a neurosurgery to provide both discriminatory and diagnostic information. Lastly, I will show evidence of anisotropic light scattering in the myelinated axons of the spinal cord and discuss the implications this may have on current photon propagation simulations in the brain, which will be integral for effective optical guidance.
Differentiating tissue types is an important aspect of guiding medical interventions whether it be for disease diagnosis or for surgical guidance. However, diseased and healthy tissues are often hard to discriminate by human vision alone and surgical navigation can be difficult to accomplish in large organs where the target structure lies deep within the body. New methods that can increase certainty in such medical interventions are therefore of great interest to healthcare professionals. Optical spectroscopy is a tool which can be exploited to probe discriminatory information in tissue by analyzing light-tissue interactions with a spectral range, resolution and sensitivity much greater than the human eye. Throughout this thesis, I will explain how I have leveraged optical spectroscopy to create, and improve, an optical guidance system for deep brain stimulation neurosurgery, specifically for the treatment of Parkinson’s disease. I will begin by describing how spectroscopic information can provide real-time feedback to a surgeon during the procedure, in the hopes of ultimately improving treatment outcome. To this end, I will present the investigation of two different spectroscopic modalities for optical guidance: diffuse reflectance spectroscopy, and coherent anti-Stokes Raman scattering spectroscopy. The advantages and disadvantages of both techniques will be discussed along with their promising translatability for this application. Following this, I will present a novel data analysis technique for extracting the tissue oxygenation from diffuse reflectance spectra with the aim of improved diagnostic information in retinal spectroscopy. While designed for the retina, the algorithm can also be used to analyze spectra acquired during a neurosurgery to provide both discriminatory and diagnostic information. Lastly, I will show evidence of anisotropic light scattering in the myelinated axons of the spinal cord and discuss the implications this may have on current photon propagation simulations in the brain, which will be integral for effective optical guidance.

The realization of wavelength scale and sub-wavelength scale fabrication of integrated optical devices has led to a concurrent need for computational design tools that can accurately model electromagnetic phenomena on these length scales. This dissertation describes the physical, analytical, numerical, and software developments utilized for practical implementation of two particular frequency domain design tools: the modal method for multilayer waveguides and one-dimensional lamellar gratings and the Rigorous Coupled Wave Analysis (RCWA) for 1D, 2D, and 3D periodic optical structures and integrated optical devices. These design tools, including some novel numerical and programming extensions developed during the course of this work, were then applied to investigate the design of a few unique integrated waveguide and grating structures and the associated physical phenomena exploited by those structures. The properties and design of a multilayer, multimode waveguide-grating, guided mode resonance (GMR) filter are investigated. The multilayer, multimode GMR filters studied consist of alternating high and low refractive index layers of various thicknesses with a binary grating etched into the top layer. The separation of spectral wavelength resonances supported by a multimode GMR structure with fixed grating parameters is shown to be controllable from coarse to fine through the use of tightly controlled, but realizable, choices for multiple layer thicknesses in a two material waveguide; effectively performing the simultaneous engineering of the wavelength dispersion for multiple waveguide grating modes. This idea of simultaneous dispersion band tailoring is then used to design a multilayer, multimode GMR filter that possesses broadened angular acceptance for multiple wavelengths incident at a single angle of incidence. The effect of a steady-state linear loss or gain on the wavelength response of a GMR filter is studied. A linear loss added to the primary guiding layer of a GMR filter is shown to produce enhanced resonant absorption of light by the GMR structure. Similarly, linear gain added to the guiding layer is shown to produce enhanced resonant reflection and transmission from a GMR structure with decreased spectral line width. A combination of 2D and 3D modeling is utilized to investigate the properties of an embedded waveguide grating structure used in filtering/reflecting an incident guided mode. For the embedded waveguide grating, 2D modeling suggests the possibility of using low index periodic inclusions to create an embedded grating resonant filter, but the results of 3D RCWA modeling suggest that transverse low index periodic inclusions produce a resonant lossy cavity as opposed to a resonant reflecting mirror. A novel concept for an all-dielectric unidirectional dual grating output coupler is proposed and rigorously analyzed. A multilayer, single-mode, high and graded-index, slab waveguide is placed atop a slightly lower index substrate. The properties of the individual gratings etched into the waveguide's cover/air and substrate/air interfaces are then chosen such that no propagating diffracted orders are present in the device superstrate and only a single order is present outside the structure in the substrate. The concept produces a robust output coupler that requires neither phase-matching of the two gratings nor any resonances in the structure, and is very tolerant to potential errors in fabrication. Up to 96% coupling efficiency from the substrate-side grating is obtained over a wide range of grating properties.
Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD

This thesis investigated factors affecting the sensitivity of nano-optical sensors that could be used for the detection of trace amounts of explosives and environmental pollutants in air. By delivering air to regions of enhanced electric field produced by metallic nanostructures, as well as using structures that localise and guide light at nanoscale levels, detection limits can be reduced.

Side-polished fiber allows access to the evanescent field propagating in the cladding of a few-mode fiber. This cladding mode is analyzed and experimentally validated to further the design of a novel class of fiber optic devices. To do this, specific modes are excited in the polished fiber using a phase-only spatial light modulator to determine spatial mode distribution. Each mode is excited and compared to the expected field distribution and to confirm that higher order modes can propagate through side-polished fiber. Based on each mode’s distribution, a side-polished fiber can be designed so that perturbations on the polished portion of the fiber effect each mode independently. By carefully analyzing the effects of identical perturbations on each mode, it is determined that each mode can be isolated based on the geometry of the polished fiber and careful alignment of the mode field. This research has the potential to advance the development of novel fiber-based sensors and communications devices utilizing mode-based interferometry and mode multiplexing.
M.S.
Fiber optic devices have seen significant advancement since the realization of the laser and low-loss optical fiber. Modern day fiber optics are commonly utilized for high-bandwidth communications and specialized sensing applications. Utilizing multiple modes, or wave distributions, in a fiber provides significant advantages towards increasing bandwidth for communications and provides potential for more accurate sensing techniques. Significant research has been conducted in both the sensing and communication field, but mode-domain devices have the capability to significantly advance the field of fiber optic devices. This thesis demonstrates the potential for side-polished fiber geometry to effect each mode independently, thus allowing side-polished fiber to be utilized for realizing novel devices such as multiplexing devices and fiber optic sensors.

This thesis is concerned with the guiding of cold atoms using optical forces, which is of great importance in the field of atom optics. Atomic beams can be used for precision sensor equipment, building nano-scale structures, construction of quantum computers and to further the understanding of the properties of atoms. Atoms are guided along light beams using the dipole force; there are two regimes under which this force works. Typically red-detuned guides are used (atoms are attracted towards the light) such guides, however, require large detuning and high powers. In this thesis we investigate the use of blue-detuned (atoms are repelled from the light) hollow light beams of moderate power (a few hundred mW) and confine atoms in the dark centre of the beams. Several magneto-optical traps (MOTs) have been constructed to exploit different guiding geometries. Hollow beams have been generated using a variety of methods; in particular the use of a computer controlled spatial light modulator (SLM) has provided great versatility and simplicity to the experimental arrangements. First, experiments were performed with a low-velocity intense source (LVIS) of atoms. A co-linear LG beam significantly enhances the observed flux, however, considerable difficulties are encountered loading atoms into oblique guides. Imaging a hole in the walls of the light tube was used to improve the loading efficiency. Second, guiding a free-falling atom cloud is performed using a non-diffracting Bessel beam. It is found that while the potential of the Bessel beam is steeper than equivalent LG beams the power distribution across the beam severely limits its usefulness. The next study investigated higher-order LG guide beams generated with an SLM. High order modes have a narrower profile so confine the atoms with less interaction with the guide beam, leading to a more natural guide (as opposed to a pushing force). Finally the SLM was used to create non-trivial beam shapes for beam splitters and interferometers.

Orientadores: Michel Zamboni Rached, Guillermo Gerardo Cabrera Oyarzún
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Nesta tese, propõe-se um novo método para realizar guiamento de átomos neutros resfriados. Este método envolve o uso da pressão de radiação por ressonância para efetuar o guiamento dos átomos através de um campo óptico (feixe) oco. Particularmente, usa-se a força de dipolo óptico e um tipo específico de campo óptico não difrativo, chamado de "Frozen Wave" (FW), na versão tradicional e estendida, para estudar o guiamento atômico. Os campos ópticos FW¿s, que são uma solução exata da equação de onda, surgem como uma resposta aos problemas relacionados com a difração e com a impossibilidade de fazer qualquer tipo de modelamento (ou localização) longitudinal e transversal de intensidade, dos campos ópticos tradicionais usados no guiamento de átomos, como por exemplo, nos campos Laguerre-Gauss e Bessel. Assim, planejam-se algumas soluções mediante os métodos tradicional e estendido que permitem criar estruturas de luz (localizadas) resistentes à difração e nas quais o padrão de intensidade longitudinal e transversal (restringido) pode ser modelado a priori. De acordo com isso, o estudo teórico do método tradicional e da generalização das FW¿s foi realizado junto com sua comprovação experimental e foram calculados os respectivos potenciais de dipolo óptico junto com a profundidade de penetração dos átomos na barreira de potencial para cada campo óptico. Nos resultados conseguiu-se modelar algumas estruturas de luz (tanto no método tradicional como no estendido) tais como um cilindro, três cilindros concatenados, um tipo de cilindro com tampa e um funil óptico, entre outras; e mostrou-se as vantagens do uso deste tipo de estruturas de luz quando comparadas com os campos ópticos tradicionais para o guiamento atômico. Finalmente, concluiu-se que usar este tipo de campos não difrativos elimina as restrições dos campos tradicionais e é possível fazer o guiamento de átomos neutros resfriados com estes tipos de estruturas de luz. O método estendido dá uma generalização que permite pensar estes tipos de estruturas de luz para aplicações mais globais nas diferentes áreas da óptica e fotônica
Abstract: This thesis proposes a new method to perform cold neutral atom guiding. This method involves the use of resonance radiation pressure to make the atom guiding along a hollow (beam) optical field. Particularly, it uses the optical dipole force and a specific type of non-diffracting optical field, called "Frozen Wave" (FW), in these traditional and extended versions, to study the atom guiding. The FW¿s optical fields, which are an exact solution of the wave equation, appear as an answer to the problems related to the high diffraction and impossibility of any type of longitudinal and transverse intensity modeling (or location) of traditional optical fields used in atom guiding, for example the Laguerre-Gaussian and Bessel optical fields. Thus, some solutions were planned by the traditional and extended methods, which allow to create localized light structures resistant to diffraction and model a priori longitudinal and transverse (restricted) intensity pattern. Accordingly, the theoretical study of the traditional method and his generalization were carried out with their experimental evidence. Also, his respective optical dipole potential was calculated with the atom penetration depth in the potential barrier for each optical field. In the results was possible to model some light structures (both in the traditional and extended method) such as a cylinder, three concatenated cylinders, one cylinder with a lid and an optical funnel, among others; and it is showed the advantages of using this type of light structures when it is compared with the conventional optical fields for the atom guiding. Finally, it is concluded that use this type of non-diffracting fields eliminates the restrictions of the traditional fields and it is possible the cold neutral atoms guiding with this type of light structures. The FW¿s extended method gives a generalization and it permits to suggest this type of light structures for more complete applications in different areas of optics and photonics
Doutorado
Física
Doutor em Ciências
141977/2013-2
CNPQ

Das IceCube Neutrino-Observatorium ist ein am geografischen Südpol im Eis installierter Neutrinodetektor. In IceCube werden Neutrinos mit Tscherenkow-Strahlung von Sekundärteilchen aus Neutrino Interaktionen detektiert. Für den Nachfolgedetektor IceCube-Gen2, werden neue und verbesserte Lichtdetektoren gesucht. Die vorliegende Arbeit beschreibt die Entwicklung eines dieser Lichtdetektoren. Dieser basiert auf Wellenlängen schiebenden und Licht leitenden Technologien. Der Detektor mit dem Namen "Wavelength-shifting Optical Module" (WOM) verwendet eine transparente Röhre, mit wellenlängenschiebender Farbe, als passiver Photonendetektor. Das in der Wellenlänge verschobene Licht wird durch Totalreflexion, zu kleinen PMTs an beiden Enden geleitet. Die Auswahl dieses Designs reduziert die Kosten und verbessert das Signal-Rausch-Verhältnis wesentlich, möglicherweise können mit dieser Lösung extragalaktische Supernova in zukünftigen Detektoren beobachtet werden. Als eine Kernkomponente wird die wellenlängenschiebende Röhre ausführlich untersucht. Verschiedene Messaufbauten und Auswertungsmethoden werden entwickelt, um diese im Anschluss zu untersuchen und zu bewerten. Iterative Verbesserungen der Materialien und des Farbauftrageverfahren als auch Messmethoden, resultieren in einer kombinierten Einfang-, Wellenlängenschiebe- und Transporteffizienz von 28,1 +/- 5,4 % der Röhre. Ein Model zur Beschreibung des Lichtverhaltens in der Röhre wird entwickelt um eine Diskrepanz zwischen Theorie und Messung zu untersuchen. Die Kombination zwischen Messung und Model, bestätigt die Aussagekraft des Models und zeigt, dass ein Großteil der Verluste beim Lichttransport zustande kommen. Darüber hinaus werden die physikalischen Eigenschaften des WOM in die IceCube Simulationsumgebung eingebaut. Der Vergleich zu einem Konkurrenzmodul zeigt eine Überlegenheit des WOM um den Faktor 1,05 +/- 0,07. Es werden Vorschläge und Ausblicke für Verbesserungen der Leistungsfähigkeit des WOMs gegeben.
The IceCube Neutrino Observatory is an in ice neutrino detector located at the geographic South Pole. In IceCube neutrinos are detected via Cherenkov light produced by secondary particles in neutrino interactions. For the upgraded detector IceCube-Gen2, new and improved light detectors are sought-after. This work describes the development of one of those light detectors based on a novel combination of wavelength-shifting and light-guiding technology. The detector named the Wavelength-shifting Optical Module (WOM) utilizes a large transparent tube, coated with wavelength-shifting paint as a passive photon detector. The wavelength-shifted light is guided via total internal reflection towards small active light detectors, at each end of the tube. This design reduces costs and improves the signal to noise ratio significantly, thereby potentially enabling extragalactic supernova detections in future detectors. As a core component, the wavelength-shifting tube is extensively investigated. Different measurement setups and evaluation techniques are developed and investigated. Iterative improvement of materials and coating techniques as well as measurement methods currently result in a combined photon capture, shift and transport efficiency of 28.1 +/- 5.4 % for the tube. Those results contrast the theoretical maximum of 74.5 %. A model is developed to describe the light propagation and loss processes in the tube and to understand the discrepancies between theory and measurement. The combination of the measurements with the model, validate the descriptive qualities of the model and show that most of the light is lost during the light propagation in the tube. Additionally, the physical properties of the WOM are included in the IceCube simulation framework. A comparison to a competing module showed that the WOM outperforms by a factor of 1.05 +/- 0.07 in photon detection numbers. Where applicable, suggestions and outlooks are given to enhance the performance of the WOM.

Ce mémoire porte sur le comportement des solitons affectés, lors de leur entrée dans un guide d'onde à fibre optique, d'une légère distorsion de profil par rapport au profil stationnaire dans le guide. Notre modèle théorique combine l'équation de propagation du champ électrique (Equation de Schrödinger Non Linéaire) et le système d'équations d'évolution des paramètres physiques de l'impulsion (issu de la théorie des coordonnées collectives). Nous dressons une cartographie générale qui dévoile une diversité insoupçonnée de comportements dynamiques au voisinage de l'état stationnaire de l'impulsion, liée à la perturbation initiale du profil de l'impulsion. Cette cartographie établit une classification des solitons en deux grandes familles, correspondant respectivement aux impulsions lumineuses qui génèrent un rayonnement au cours de leur propagation et aux impulsions non rayonnantes. Au sein de chacune de ces deux grandes familles d'impulsions, nous démontrons l'existence de comportements atypiques, que nous qualifions de solitons hyperthermiques (solitons chauds), solitons hypothermiques (solitons froids), et solitons isothermiques, qui correspondent respectivement à des impulsions qui se propagent de manière hautement stable avec un niveau d'énergie supérieur, inférieur, et égal à l'énergie de l'état stationnaire. Aux frontières des domaines d'existence de ces différents types de soliton, nous trouvons des comportements hybrides, correspondant à des solitons qui se refroidissent en cours de propagation suite à une perte significative d'énergie provoquée par un rayonnement intense, et qui changent d'état (de l'hyperthermie à l'hypothermie, ou de l'isothermie à l'hypothermie). Enfin, l'onde de rayonnement émise par une impulsion lumineuse n'est pas identifiée comme étant un processus continuel, mais plutôt comme une bouffée d'énergie émise en début de propagation, et sa suppression dans le guide d'onde est considérée comme réalisable

In this thesis we show several modelling tools which are used to study nonlinear photonic band-gap structures and microcavities. First of all a nonlinear CMT and BPM were implemented to test the propagation of spatial solitons in a periodic device, composed by an array of parallel straight waveguides. In addition to noteworthy theoretical considerations, active functionalities are possible by exploiting these nonlinear regimes. Another algorithm was developed for the three-dimensional modelling of photonic cavities with cylindrical symmetry, such as microdisks. This method is validated by comparison with FDTD. We also show the opportunity to confine a field in a region of low refractive index lying in the centre of a silicon microdisk. High Q-factor and small mode volumes are achieved. Finally the characterization of microdisks in SOI with Q-factor larger than 50000 is presented

We aimed to provide optimal and controlled growth mechanisms that determine the fate of cells by designing a novel polymeric, bio-functionalised 3-dimensional artificial Nanofibrous Extracellular Matrix (NF-ECM) that recapitulates the natural microenvironment of cells. We initially reviewed current cell-expansion methods, and clinically feasible protocols for tissue engineering applications. They are often based on conventional 2-dimensional tissue culture plates that usually require xenogenic coating substrates or feeder-cells to maintain their characteristics. Propagating cells in a 3-dimensional architecture, rather than in the conventional 2-dimensional flat monolayers, can be advantageous for many regenerative applications and biological or disease modelling studies. Furthermore, such 3-dimensional culture systems might be crucial in developing a bioreactor-based design that provides finely controlled environmental conditions that would reliably propagate 3-dimensional multilayered cell organisation or spheroids on a large scale. Furthermore, the ability to expand cells in the absence of animal-derived products is a necessary condition for clinical application.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Dentistry and Oral Health
Griffith Health
Full Text

Effective daylighting can substantially reduce the energy use and greenhouse gas emissions of commercial buildings. Daylight is also healthy for building occupants, and contributes to occupant satisfaction. When productivity improvements are considered, effective daylighting is also highly attractive financially. However, successful daylighting of sub-tropical buildings is a very difficult task, due to high direct irradiances and excessive solar shading. A device was created that combined effective solar shading and efficient daylight redirection. The micro-light guiding shade panel achieves all objectives of an optimal daylighting device placed on the façade of a sub-tropical, high rise office building. Its design is based on the principles of non-imaging optics. This provides highly efficient designs offering control over delivered illumination, within the constraints of the second law of thermodynamics. Micro-light guiding shade panels were constructed and installed on a test building. The tested devices delivered daylight deep into the building under all conditions. Some glare was experienced with a poorly chosen translucent material. Glare was eliminated by replacing this material. Construction of the panels could be improved by application of mass-manufacturing techniques including metal pressing. For the micro-light guiding shade panel to be utilised to its full potential, building designers must understand its impact on building performance early in the design process. Thus, the device must be modelled with lighting simulation software currently in use by building design firms. The device was successfully modelled by the RADIANCE lighting simulator. RADIANCE predictions compared well with measurements, providing bias generally less than 10%. Simulations greatly aided further development of the micro-light guiding shade panel. Several new RADIANCE algorithms were developed to improve daylight simulation in general.

Effective daylighting can substantially reduce the energy use and greenhouse gas emissions of commercial buildings. Daylight is also healthy for building occupants, and contributes to occupant satisfaction. When productivity improvements are considered, effective daylighting is also highly attractive financially. However, successful daylighting of sub-tropical buildings is a very difficult task, due to high direct irradiances and excessive solar shading. A device was created that combined effective solar shading and efficient daylight redirection. The micro-light guiding shade panel achieves all objectives of an optimal daylighting device placed on the façade of a sub-tropical, high rise office building. Its design is based on the principles of non-imaging optics. This provides highly efficient designs offering control over delivered illumination, within the constraints of the second law of thermodynamics. Micro-light guiding shade panels were constructed and installed on a test building. The tested devices delivered daylight deep into the building under all conditions. Some glare was experienced with a poorly chosen translucent material. Glare was eliminated by replacing this material. Construction of the panels could be improved by application of mass-manufacturing techniques including metal pressing. For the micro-light guiding shade panel to be utilised to its full potential, building designers must understand its impact on building performance early in the design process. Thus, the device must be modelled with lighting simulation software currently in use by building design firms. The device was successfully modelled by the RADIANCE lighting simulator. RADIANCE predictions compared well with measurements, providing bias generally less than 10%. Simulations greatly aided further development of the micro-light guiding shade panel. Several new RADIANCE algorithms were developed to improve daylight simulation in general.

La thèse propose l’utilisation d’une pince active instrumentée en force pour automatiser l’assemblage des MOEMS 3D hybrides. Chacun des doigts de la pince instrumentée est composé d’un actionneur piézo-électrique et d’un capteur de force piézorésistif intégré. Le capteur de force intégré présente des performances innovantes par rapport aux capteurs existants dans l’ état de l’art. Cette pince offre la possibilité de mesurer les forces de serrage appliquées par la pince pour saisir un micro composant et d’estimer les forces de contact entre le micro composant et le substrat de micro-assemblage.Un modèle dynamique et non linéaire est développé pour la pince instrumentée. Une commande hybride force/position est utilisée pour automatiser le micro-assemblage. Dans cette commande, certains axes sont commandés en position et les autres sont commandés en force. Pour les axes commandés en force, une nouvelle commande fondée sur une commande en impédance avec suivi de référence est proposée selon un principe de commande non linéaire par mode glissant avec estimation des paramétres en lignes. En utilisant le schéma de commande hybride force/position proposé, une automatisation de toutes les tâches de micro-assemblage est réalisée avec succès, notamment sur un composant flexible à guider dans un rail
This work proposes the use of an active microgripper with sensorized end-effectors for the automationof the microassembly of 3D hybrid MOEMS. Each of the two fingers of the microgripper is composedof a piezoelectric actuator with an integrated piezoresistive force sensor. The integrated force sensorpresents innovative performances compared to the existing force sensors in literature. The forcesensors provide the ability to measure the gripping forces applied by the microgripper to grasp a microcomponentand estimated the contact forces between the microcomponent and the substrate ofmicroassembly. A dynamic nonlinear model of the microgripper is developed. A hybrid force/positioncontrol is used for the automation of the microassembly. In the hybrid force/position control formulation,some axes are controlled in position and others are controlled in force. For the force controlledaxes, a new nonlinear force control scheme based on force tracking sliding mode impedance controlis proposed with parameter estimation. Using the proposed hybrid force/position control scheme, fullautomation of the microassembly is performed, notably for the guiding of a flexible component in arail

博士
國立交通大學
光電工程所
91
Optical data storage industries are continually growing with rapid progress of computer, multimedia, and network markets. In this trend, technologies capable of recording more information thus become increasingly demanded. Since optical heads are a key component of the recording system, developing a high-spatial-resolution, high-optical-efficiency and small-sized optical head is thus essential to enable the system more competitive in price and performance. For increasing the recording density, a near-field optical approach using a solid immersion lens (SIL) was developed. The effective numerical aperture (NAEFF) of the system can be achieved above theoretical upper limit of 1.0 in air. The air spacing between the SIL and the recording medium is an important factor that influences the focused spot quality. Compared with gap width h = 0 nm, the spot width is increased by 90 % at h = 300 nm. The primary factor causing increased spot size at larger air spacing is due to the gap-induced aberration, which is introduced by the phase and amplitude apodization when the incident light passes through the air gap. On the other hand, the peak intensity of the focused beam is decreased by 85 % when the gap width h changes from 0 to 300 nm. The reflection coefficients of the thin-film structure are both angle and polarization dependent, the contrast of readout signal is a different function of air gap width for x and y polarizations. For an x-polarized incident beam, the simulation shows that a method by filtering y-polarized light results in a factor 1.0 to 1.35 higher than non-polarized detection for signal contrast in phase-change media. We then demonstrated a microfabrication of SIL array by using a 248 nm excimer laser micromachining with a gray-tone mask photolithography. With pre-correlation to the nonlinear exposure process, a 30-mm-radius hemispherical SIL array was achieved with a deviation of less than 5%. The fabricated SIL array was used with a 0.54 NA objective to achieve 0.87 effective NA measured by the knife-edge scanning. In order to make the optical head smaller and lighter for fast access, we designed and fabricated a hyperbolic-shaped microlens on a single-mode fiber (SMF) to achieve the focused spot 1/e2 = 0.82 mm (x-direction) and 0.89 mm (y-direction) at 145 mm working distance by the discharged arc method. To overcome the drawbacks of low NA and fragility of the fiberlens-type optical head, a well-controlled mechanical structure with a fiberlens, a SIL and a submicron aperture was proposed as a heat source for near-field recording. Through this structure, a below-diffraction-limited submicron aperture (600 nm) within the diffraction-limited fiberlens illumination was used to realize a super small spot size with 10-1 throughput efficiency. This small-size (3mm*3mm*500mm) highly integrated module can be driven by a radial actuator for beam steering, which can potentially function as a flying head in next-generation optical storage systems.

Contact-free trapping and manipulation of light absorbing micrometer and nanometer-scale particles in air and in vacuum utilises radiation pressure, which results from momentum transfer from photons, and a pressure-dependent thermal force, caused by momentum transfer from gas molecules to the confined particles. Both forces are linearly proportional to the illuminating laser intensity, and both push the particles towards regions of lower intensity. While the radiation pressure of light was predicted and described more than a century ago, the theory of thermal forces, the so called photophoretic force, is still under development. It depends on a number of poorly described factors, such as the temperature gradient across the illuminated particle and thermal creep of heated gas along the particle surface due to temperature and pressure gradients. In this thesis I use doughnut-shaped structured laser beams to levitate and guide light-absorbing micron-size particles aiming to uncover the optically induced forces in air at variable pressure ranging from 10-2000 millibar. First, I designed and built a counter-propagating optical pipeline to uncover the influence of polarisation on the particle movement. Second, I designed and constructed a vertically directed diverging vortex beam trap, a `funnel' trap, to conduct a quantitative evaluation of the photophoretic force and trapping stiffness by levitating graphite particles and carbon-coated glass shells of calibrated sizes in a carefully characterised vortex beam. Third, from the measured size of the particles and the position of the particle in the beam on the one hand, and the known density of the particles and the intensity distribution of the funnel trap on the other hand, I characterised the optically induced thermal forces in the axial and transverse directions. Fourth, I compared the contribution of thermal force to the light-pressure force and their dependence on atmospheric pressure. Based on the results of my experiments I determined the parameter space for guiding particles with hollow-core vortex and Bessel beams, taking into account the particle speed, size, and offset from the laser axis, all linked to the optical beam properties such as beam divergence, optical polarisation and power. The results of this thesis are used in the development of a touch-free optical system for pin-point delivery of macromolecules to the X-ray focal spot at the Free Electron Laser facility at the DESY (Deutsches Elektronen-Synchrotron) synchrotron in Hamburg, Germany, for coherent diffractive imaging experiments on nanometer-scale morphology. I conclude with a discussion of avenues for future work in contact-free manipulating of particles with structured laser beams to enhance significantly the efficiency of nanometer-scale morphology of proteins and biomolecules.

碩士
淡江大學
電機工程學系碩士班
98
In this thesis, an optical-flow based tracking system is implemented. With the optical-flow perturbation detect algorithm, the robot can follow the hand waving in scene, and reach the goal of visual following. The system architecture in this thesis is based on linux system, and use OpenCV library to implement optical-flow perturbation detect algorithm. There are 4 steps of optical-flow perturbation detection: (1) Get difference between two frames, (2) Remove background noise, (3) Calculate the sum of perturbation energy, (4) Gather the Region Of Interest (ROI) from image. For design and implement action, this thesis designs a robot to move in constant speed, improve the result of optical-flow algorithm to detect the waving hand, and implement a Proportional and Integral Controller by Verilog HDL on FPGA to control the motor. From the experiment result, the method of this thesis can lead the robot to follow the waving hand, reach the goal of optical-flow tracking.

碩士
國立中興大學
材料科學與工程學系所
98
Abstract The current trend of TFT displays is towards energy efficiency and carbon reduction and the light-emitting diodes (LEDs) have been utilized as the emitter in the backlight module. In this period, the LED replaces the CCFL light source gradually and it performs better optical performance obviously as a result of creating the module thinner. Currently, the ultra-thin light guiding plates are manufactured by the ejection molding method. However, the ejection molding can only be applied for small-size light guiding plates. It is well known that the LED backlight modules are moving in large size. Therefore, the screen printing becomes a dominant technique in future large-size light guiding plates. This thesis focuses on the design of LED backlight module of the 24” light guiding plates. The parameters of the screen printing process for the light guiding plate are also investigated. The improvement and optimization of the optical pattern and printing process were confirmed to be the critical issues when the thickness of the light guiding plate is decreased. For the middle and larger light guiding plates, the major manufacture issue is lack of shelter, which will result in the dot size decreasing in the design stage. Nowadays, the solvent ink with polyester screen only have 30 percent yield rate in the conventional screen printing process. It was found that the combination of UV ink printing with steel silk screen have achieved the yield rate of over 95% in the printing process. As a result, this process can not only accelerate the commercialization of the large-size ultra-thin light guiding plate import, but also improve the performance of light guiding plates with efficient cost reduction margin.

碩士
國立臺灣科技大學
電子工程系
98
For saving energy and healthy lighting, many researches focus on the sunlight illumination system. A Natural Light Guiding System can be separated into collecting, transmission, and lighting parts. With a cascadable concentrator in the collecting part, the transmission part will use large number of lightpipe. It means the most of cost is on the transmission part. The role of the optical coupler has become more and more important for Nature light guiding system. With the useful design, one can get the better efficiency. The purpose of this paper is to report the research of optical coupler. We present a concept that combines stepped structure with light pipe. In this paper, we utilize the stepped structure optical coupler. It was found that the stepped structure can maintain the output angle successfully. In conclusion, the features of stepped structure optical coupler make the coupler system easier to couple and maintain the output angle.

博士
國立陽明大學
生醫光電研究所
100
The first part of this thesis is to develop a method which can fine induce the spontaneous movement of cells. This study is based on the research of guiding the neural growth by using the infrared laser light. We illuminate the lamellipodia of cells by using 405 nm and 1064 nm laser light then observe the movement of lamellipodia. In the result, the 405 nm and 1064 nm laser light induce cell lamellipodia retraction and protrusion respectively. The most effective parameters of 405 nm laser light to induce lamellipodia retraction are 0.1 mW of power and 100 msec of illumination duration. On the other hand, the most effective parameters of 1064 nm laser light to induce lamellipodia protrusion are 4 mW of power and 10 sec of illumination duration. We also calculate the increment of local temperature in DMEM culture medium around the 405 nm and 1064 nm laser light. The results are = 5×10-7 oC and = 2×10-2 oC so the increment of local temperature is negligible. We find that the 405 nm laser light reduces the actin distribution near the illuminated site, while the 1064 nm light increases the density of actin. In the second part of this thesis, we improve the system which was projected the 473 nm optical micropattern with 0.4 W/cm2 of power on the bottom of culture dish. The optical pattern will generate the light fence to culture and confine the region of cell growth. The lung cancer cells can migration and proliferation as normal cultured cells inside a 50 um width of triangle light fence but can not migrate to the outside of the light fence. The cells inside the light fence form a complete triangle colony after a few days. In order to confirm the correlation between the pattern of cell colony and light fence, we create a 50 um width of rectangle light fence on the bottom of culture dish. The cells inside the light fence form a complete rectangle colony after a few days. The results are similar to the experiment of the triangle light fence. We change the cell line with A549 and demonstrate that the micropattern culture is cell line independent. After the data analysis and quantification, the discrepancy between the pattern of cell colony and light fence is about 15 %. It means that the pattern of cell colony has a great resemblance to the light fence. Furthermore, the effect of cell viability affected by light fence is very small. We perform a complete process of the wound healing by using the dynamic light fence. The wound healing is appropriate for demonstrate the controlled ability of the light fence in the spatial and temporal domains. A complete process of the wound healing includes the three parts. First is to generate two independent cell colonies by using light fence (0-24 hr). Second is to maintain the micropattern of two independent cell colonies (24-48 hr). Finally is to carry out the wound healing (48-96 hr). It also manifests that the system can maintain and control the micropattern of the adhere cells in a long-term experiment. We also estimate the effect of the local risen temperature of DMEM culture medium around the 473 nm light fence at 0.4 W/cm2. The result shows that the local risen temperature is 4×10-6 ºC. Therefore we exclude the effect of the local risen temperature from the mechanism which affects the cell behaviors. On the other hand, we observe that the intercellular mitochondria were damaged by the 473 nm light fence. We surmise that 473 nm light fence destroy the mitochondria may be the mechanism of the micropattern culture of adhere cells by using light fences. In future works of this thesis, there are three parts of the applied studies. The first part is using the light fence to study the cell dynamics, cell behaviors and cell-cell interaction. The second part is combining the light fence and biochip which generates the electric field or delivers the drugs. We aspire to develop a technique which can perform multi-stimulation on the cells.

碩士
國立成功大學
工程科學系
107
As of currently, many optical application in microstructures are being made via multiphoton excitation (MPE) attached on semiconductors. However, there is a lack of research regarding direct fabrication on semiconductor lasers with combination of optical structures that consists of both the abilities to guide and collimate the laser beam. In this thesis, MPE technique is utilized to create three dimensional (3D) structures via polymerization in trimethylolpropane triacrylate (TMPTA) solution. Due to the fact that the precision of MPE is in focal volume, the sectioning effect is significantly better than single-photon excitation. With this technique, the high spatial resolution of the 3D waveguide devices has the ability to collimate and redirect laser beam can be directly fabricated on specific location of laser diodes. The main mechanism of the multiphoton-induced fabrication technique was done in TMPTA solutions, the solution contains TMPTA as the reactive monomer, rose Bengal (RB) as the photoactivator, and trimethylamine (TEA) as co-initiator. In this process, the photoactivator is activated through two-photon absorption (TPA) of femtosecond laser to produce the two-photon polymerization (TPP). In addition, femtosecond laser can generate enough photon energy density within focal volume. Hence, the free radicals are produced from the reaction and the energy is then transferred to the monomers. After having the energy transferred, the TMPTA monomers attach with each other through covalent bonding and form a precise, delicate, transparent and rigid structure on selected area in micron-scale that standard fabrication methods could find difficult to work with. The objective of this thesis is to use TPP to fabricate a combination of photonics devices directly on edge-emitting laser diode (EEL). Through guiding the laser in the direction similar to vertical-cavity surface-emitting laser diode (VCSEL) then collimate the divergent laser beam by a lens. VCSEL is the trend of laser diode technology since it is economical to manufacture, easier to couple with optical fiber. And the circular-like laser beam from VCSEL can be collimated more efficiently. However, due to the fact that VCSEL has a short cavity, it is difficult to generate higher power output. On the other hand, EEL have long cavity to generate stronger laser. By attaching the optical devices to EEL, this semiconductor laser will then be able to have much greater value of power output and the direction is relatively close to VCSEL for better versatility and flexibility in potential electric device applications. In conclusion, this thesis has concluded that it is possible to have direct fabrication through MPE to construct optical devices on specific location on a semiconductor laser with designate functions and properties. Though there are some defects exist, it could be improved with adjustment on design and process, and the future potential continues.

碩士
國立交通大學
光電工程研究所
108
In recent years, GaN-based devices have attracted considerable attentions by researchers from academia and industry, which can be applied in optical communications, optical storage, solid state lightning and so on. Futhermore, GaN-based VCSEL even playing an important role in 3D sensing and LiDAR. In this paper, we design the GaN-based VCSEL with optical guiding structure by modulating compensation layer thickness to prevent the anti-guiding effect. In process, laser lift-off, wafer bonding and CMP techniques were adopted in order to fabricate dielectric type of vertical-cavity surface-emitting lasers with optical guiding and anti-guiding structure. Also,we optimize the measurement to control cavity length precisely during CMP. We demonstrate the anti-guiding GaN-based VCSEL with different aperture, which shows the smaller aperture, the anti-guiding effect more obvious. And the threshold current density decreases with the distance between the cavity mode and gain peak. On the other hand, we also demonstrate the optical guiding GaN-based VCSEL, shows the lower threshold current density 25.4 kA/cm2. In a future study, we will investigate the better optical guiding structure, in order to make the threshold current density lower.

碩士
國立臺灣科技大學
電子工程系
98
Recently, many researches focus on the sunlight illumination to provide for indoor lighting and saving energy which is called Nature Light Guiding System. For indoor lighting, it can provide the same brightness as the tradition lamp and it can also save 80% energy with the lamp. In order to use the sunlight effectively, we design an optical to control and change the direction of the transmitted light. For the past optical switch, the efficiency is unable to achieve the desired result. To solve this problem, we use two lenses to redesign an optical switch and the parameters are calculated by the Q-U method.

碩士
中華科技大學
機電光工程研究所碩士班
101
Recently, all people emphasize the environmental friendly concepts. The green industry is fast developing. More and more company are taking plunge in all kinds of green products to sell. Among these products, the so-called Sun Guiding System is one of the most environmental and cleanest part worth for us to exploit. If we are able to guide natural light from outside to inside to illuminate our indoor spaces, we can say good bye to electricity, save energy, and save money from our pockets. The Sun Guiding System is composed of the modules, namely, sun collection, transmission, and emission. This paper is focused on the emission module that includes a TIR lens specially designed for optical- fiber to connect and emit natural light for commercial lighting by the tool of optical simulation software. Hopefully through the above simulation and study, an appropriate optical device – lens for optical-fiber can be designed to adjust the illuminance, to prevent glare, or to adjust the light angles, and then apply to different business stores, such as coffee shop, cloth shops or even bookstores.

For more than three centuries we have been watching and studying microscopic phenomena behind a microscope. We discovered that cells live in a physical environment whose predominant factors are no longer those of our scale and for which we lack a direct experience and consequently a deep intuition. Today’s computational approaches to microscopy allow high frame rate volumetric reconstructions from 2D holographic patterns that encode the full 3D structure of the sample. On a parallel track, modern holographic spatial light modulators integrated in optical tweezers setups allow to dynamically arrange complex many-particles systems in precise 3D configurations. In this regard, highly efficient iterative algorithms ensure quick hologram computation for the live refresh of the spatial light modulator. In this PhD thesis, we present a novel instrument which, by integrating holographic and virtual reality technologies, allows the user to be completely immersed in a dynamic virtual world which is the simultaneous replica of a real system under the microscope. We use a 3-axis implementation of holographic microscopy for fast 3D imaging and real-time rendering on a virtual reality headset. At the same time, hand tracking data is used to dynamically generate holographic optical traps that can be used as virtual projections of the user hands to interactively grab and manipulate ensembles of micro-particles or living motile cells, like swimming bacteria. The strategy used can be flexibly adapted to different sample types by integrating suitable 3D imaging techniques into the system. The dynamics of larger eukaryotic cells is observed using the gradient light interference microscopy label-free technique, which provides quantitative height maps of the specimen. Our interface allows a more direct interaction with systems at the micron scale. The user can immersively explore a microscope sample of colloidal particles or living cells, analyze their motility interactively and with quantitative tools, control optical traps to catch, reorient, probe and eventually release individual bacterial cells. A further project is also presented, in which the diffraction-limited laser spot is exploited for lithographic purposes. Arbitrary shaped micro-structures with submicrometer 3D resolution can be fabricated by direct laser writing on photosensitive resins. Using this strategy, we developed an optical reaction micro-turbine made of curved micro-fibers that can maximally exploit light’s momentum to generate a strong, uniform, and controllable torque. The real-time fabrication of custom micro-structures as well as their operation and manipulation within an immersive environment represent intriguing add-ons to implement in our virtual reality interface.

Photonic crystals can be thought of as 'optical analogues' to electronic semiconductors, and have been widely studied for their periodically-varying indexes of refraction. This allows for controlling the propagation of photons inside the crystals, similar to the way electrons are excited in a semiconductor crystal. The superprism phenomenon is the extremely large angular dispersion experienced by a light beam when entering a photonic crystal. This arises from the anisotropy of the photonic band structure which can be present even in systems without a complete photonic band gap. Here, we describe theoretical and experimental investigation of the superprism effect in three-dimensional macroporous polymer photonic crystals formed from colloidal crystal templates. We explore the extreme sensitivity of the propagation direction to various input parameters, including the input angle, the light frequency, and the composition of the photonic lattice. Such effects can be exploited for sensing and filtering applications.

碩士
國立臺灣科技大學
營建工程系
101
Multiple labor shifts system is commonly used in construction project to achieve the desired deadline. However, evening and night shifts may bring negative impacts and the application must be as low as possible. In this study, a new multi-objective optimization algorithm has been proposed and applied to solve multiple labor shifts problem. The proposed approach, MO-DCPSO, presents a new multi-objective optimization algorithm based on DCPSO which hybridizing dynamic guiding and chaotic search concepts with PSO. The multiple labor shifts problem has three objectives to minimize: project duration, project cost and total labor hours in evening and night shifts, while also maintaining all scheduling constraints, such as job logic and daily resource limit. An application example is used to illustrate the performance of the proposed approach. This study also builds NSGA-II and MOPSO model for comparison methods. The obtained Pareto front may provide solutions for construction practitioners to facilitate the decision making for construction trade-off problems.

碩士
中原大學
機械工程研究所
99
Due the manufacturing demand of miniature parts, Non-MENS micro manufacturing has become one of the important developing manufacturing technologies. A micro machine tool with characteristics of low cost and high performance plays an important role in the micro machining field. In this study, a new configuration design for the dual-toggle-type micro machine tools was proposed. The new design improves the drawbacks of the previous design made by our lab. After optimization process, the design provides the advantages of small floor space, long travel length, and small variations in feed resolution. Besides, to shorten the design time, this research also developed a design guiding system written in MATLAB. This system can guide a user to complete the design of the important component of a new dual-toggle-type machine tool based on the defined floor space or travel length. In addition, the volumetric error analysis function and the error sensitivity analysis function were also built in the system to provide users the reference for selection of optimal machining region or continuous design improvement of the machine.

The field of atom optics has progressed rapidly over the past 20 years since the realisation of Bose-Einstein condensation, such that the wave behaviour of atomic gases is now routinely demonstrated. Furthermore, the study of quantum atom optics, which goes beyond a ‘mean-field’ description of quantum systems to consider the behaviour of single particles, has demonstrated both the similarities between photons and massive species, and their differences as a result of the internal structure and external interactions of atoms. An important class of observable quantities which allow such effects to be measured are nth order correlation functions, which can be interpreted as a result of either particle or wave behaviour. These functions provide a statistical description of fluctuations in n-tuples of particles in a source, which rigorously defines concepts such as coherence. The quantum statistics of a Bose-Einstein condensate should be the same as that for an optical laser, while an ideal thermal Bose gas matches the behaviour of incoherent light. However, correlation measurements can also be used to quantify the influence of interactions, dimensionality, confining potentials and waveguides, and the difference in quantum statistics between fermions and bosons, which illustrates the rich range of behaviour exhibited by atomic gases. In this thesis, several aspects of quantum atom optics are explored with experiments using ultracold metastable helium, a species with the unique advantage of facilitating simple single-atom detection with high resolution, while still allowing Bose-Einstein condensates to be formed. The coherence of atomic systems is shown to be maintained when outcoupled as pulsed atom lasers, and the long-range order characteristic of Bose-Einstein condensates is demonstrated to third order for the first time. Conversely, thermal bunching is observed for a variety of atomic systems, including the measurement of correlation functions up to sixth order with near-ideal interference contrast. These results clearly demonstrate the correspondence between the quantum statistics of photons and atoms as was formalised by Glauber, as well as confirming the validity of applying Wick’s theorem to simplify the statistics of atomic gases. Correlation functions are also shown to be an ideal tool to probe the quantum state of an ultracold gas, and were used to observe the phenomenon of transverse condensation in an elongated Bose gas, as well as characterise the mode occupancy of matter waves guided by an optical potential. Ultracold metastable helium is also suitable for exploring other fundamental topics in quantum optics such particle/wave duality. The notion of complementarity stimulated long running philosophical discussions about how apparently mutually exclusive behaviours can coexist, which culminated in Wheeler devising his famous ‘delayed choice’ gedankenexperiment. A proposed experimental method to realise Wheeler’s experiment with ultracold atoms is discussed, and preliminary measurements presented which indicate that the completion of this experiment could be achieved in the near future. Not only is this of interest in its own right, but the implementation of this experiment has also developed techniques which may enable further studies in quantum atom optics such as investigations of the Hong-Ou-Mandel effect and quantum entanglement with massive particles.