Controlling nano to microscale structuration enables one to alter a material’s optical, wetting, mechanical, and chemical properties. Structuration on this scale can be formed from spherical building blocks; in particular, monodisperse, spherical colloids assemble into crystals that can be used to template an ordered, porous structure known as an inverse opal. The structure’s porosity and periodicity provide control over both light (photonic effects) and fluid flow (wetting effects). Controlling the composition allows chemical functionality to be added to the ordered, porous structure. Inverse opals are widely used in many applications that take advantage of these properties, including optical, wetting, sensing, catalytic, and electrode applications; however, high quality structures are necessary to maintain consistent properties. Many of their properties stem from the structure itself, so controlling inverse opals’ structure (including the local composition) provides the ability to control their properties, with the potential to improve some applications and potentially enable additional ones. This thesis explores how molecular precursors can be used to control colloidal assembly and therefore alter the optical and wetting properties of high quality inverse opals. Using a bio-inspired approach, highly ordered, crack-free, silica inverse opals can be grown by co-assembling the colloidal template with a sol-gel matrix precursor using evaporation-induced self-assembly. Using sol-gel chemistry, the size, shape, and charge of the precursor can be controlled, which can be used to tune the colloidal assembly process. Here, we use the sol-gel chemistry of the precursors to control both the morphology and composition of these photonic structures. In particular, temperature-induced condensation of the silica sol-gel matrix alters the shape of an inverse opal’s pores (Chapter 2), and silica and titania precursors can be mixed to make hybrid oxide structures (Chapter 3). Additionally, rationally designed precursors enable the fabrication of crack-free inverse opals in materials beyond silica, which we show for titania as a proof-of-concept (Chapter 4). By controlling the structure and composition with sol-gel chemistry, we can tailor both the optical and wetting properties, as discussed in the second part of each chapter; these properties have important effects for the various applications. In this way, sol-gel chemistry can be used to assemble inverse opals with complex functionality. / Chemistry and Chemical Biology

There are unique challenges in the fabrication and testing of optical semiconductor devices because, unlike typical silicon semiconductor devices, which can be tested cost-effectively on the wafer, many optical devices can only be 'fully' tested once the individual die is bonded to a heat sink. As a result, both the manufacturing process and test strategy need to be capable of predicting yields and product quality attributes based on limited sampling from a batch of the product. The large number of product quality and process variables that are measured for each device when it is manufactured makes it almost impractical to manually analyze them for valuable decision-making information. There is a need for understanding the complex, interactive effects of process variables on the product quality variables as well as automated analysis and discovery tools for extracting useful knowledge from the raw data. Such knowledge could have a significant impact on productivity and quality improvement. The objective of the present study is to identify useful correlations amongst the numerous process variables and to develop simple empirical models to predict important process quality indicators. Quality is assessed using statistical data analysis, focusing on the primary functions of major failures. Validation of the data set also demonstrated that linear models were accurate in predicting new data points for some of the output variables, whereas the variation of some output variables could not be explained using the available industrial data bank. Some models were powerful in making predictions and to provide a clearer insight in determining the key factors in manufacturing of BHet. BHet is a directly modulated laser operating at 2.5 Gb/s and reaches up to 360 km. Application of this research for failure prediction at an early stage of the manufacturing line could result in a dramatic reduction in the number of defective wafers that are completely processed and thereby lowering the overall manufacturing cost.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Imager un milieu diffusant épais par voie optique interdit l'utilisation des techniques d'imagerie optique conventionnelles du fait de la faiblesse du signal balistique. L'imagerie acousto-optique de la lumière diffusée permet d'obtenir une imagerie de l'absorption optique locale avec une résolution transverse millimétrique. Elle s'appuie sur un faisceau acoustique focalisé qui engendre par interaction acousto-optique une modulation de la phase du champ lumineux diffusé. Les détections cohérentes du signal optique modulé acoustiquement se trouvent cependant souvent limitées par la faiblesse de leur étendue optique ou de leur bande passante. Notre expérimentation s'appuie sur une détection photoréfractive hétérodyne reposant sur une holographie dynamique à 1064nm construite autour d'un cristal photoréfractif massif d'Arsenure de Gallium, pour pallier à ces deux limitations. Par ailleurs, pour obtenir une résolution millimétrique selon l'axe de propagation ultrasonore, nous avons développé une technique de modulation aléatoire de phase du faisceau acoustique et du faisceau lumineux qui crée une zone de cohérence temporelle contrôlée au sein même du milieu diffusant. La mise en oeuvre de ces techniques ont permis d'imager avec des résolutions millimétriques des échantillons diffusants de caractéristiques proches des tissus biologiques sur une épaisseur de 3cm.