The 2010 explosion of BP’s Deepwater Horizon oil rig was an environmental disaster unparalleled in United States history. Because of this, there has been a great deal of research studies regarding the matter. The purpose of this study was to determine what inshore fishing guides in the Tampa Bay Area feel should be a response to future oil spills using Image Repair Theory, as well as how this important group of stakeholders felt about the image repair responses employed by BP in the wake of the spill. In depth interviews were used to gather data and answer the pertinent research questions, which also generated follow up questions. The findings showed Tampa Bay Area captains feel that BP’s responses in the wake of the spill were inadequate in alleviating the situation. The captains felt that better planning on the part of oil companies is needed and also that oil companies should be mortified and have clear and decisive plans for correcting the situation as well as alleviating the effects of said spill on the pertinent publics.

Five study guides prepared for two productions of I, Claudia by Kristen Thomson will serve as a case study to determine the nature and orientations of the tools provided by theatre companies to pedagogues, who in turn teach students how to understand and read theatrical performance. More specifically, this case study will seek to explain how processes typical of “cultural mediation” help students accumulate what Pierre Bourdieu names “cultural” or “social capitals”, both necessary when training future citizens. This thesis will thus serve as a first critique of the workings, strengths and failings of a sociological mechanism typical of English Canadian theatre designed to help teachers mediate theatre and create more informed audience members.

The Scholastic Aptitude Test (SAT) is taken each year by two fifths of the high school graduates (Cameron, 1989). The perception that high SAT scores will either open the door of selective colleges and generate scholarships or that low SAT scores will close off opportunities for the rest of one’ life, makes virtually every student who invests the three hours of time required to take the test extremely anxious about doing as well as possible (Whitla, 1988). Significant relationships between identified preparation techniques and the perceived effectiveness of those techniques by students and staff can be very useful information for educators when counseling and/or assisting students who want to improve their performance on the SAT. This study describes perceptual opinions from students, teachers, counselors, and administrators from 10 Portland, Oregon metropolitan area schools about the effectiveness of three SAT preparation techniques. The following research questions were examined: 1. What is the perceived effectiveness of three SAT preparation techniques: SAT computer programs, SAT preparation classes, and specific SAT information taught in general classes? 2. Are students who regard the SAT as important more likely to know about, use, and perceive effective the three preparation techniques than students who do not? 3. Are students who regard the SAT as important more likely to perceive their teachers or administrators as valuing the SAT than students who do not? 4. Are students who perceive that their teachers or administrators regard the SAT as important more likely to perceive the preparation techniques effective than students who do not? The results of this study indicated some specific groups of students and teachers did perceive one preparation technique to be effective. Their perceptions validated belief in specific SAT information taught in general classes as an effective preparation technique. It also revealed that there was lack of awareness, use, and perceived effectiveness of both SAT computer programs and SAT preparation classes. Lastly, the study showed that both students and teachers who perceived the SAT to be important, agreed that their administrators valued the SAT.

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Le développement des télécommunications optiques à haute capacité fait des multiplexeurs en longueur d'onde un sujet brûlant des récentes recherches. Dans cette thèse, nous proposons et démontrons des réseaux sélectifs planaires ou (Arrayed Waveguide Grating, AWG) basés sur une plateforme de Nitrure de silicium (SiN) comme multiplexeur ou démultiplexeur. Dans le premier chapitre, nous comparons les guides d'onde en silicium et en nitrure de silicium et confirmons que le SiN sera considéré comme la plateforme principale de ce travail. Nous présentons des simulations des guides d'onde de SiN qui forme les AWGs, incluant les guides d'onde planaires, les guides d'onde à bande, les guides d'onde courbés et les guides d'onde fuselée utilisant FDTD solution et Mode solution d'Ansys Lumerical. L'influence des paramètres de conceptions des AWGs en SiN tels que la longueur focale, la distance séparant les guides d'onde, l'espacement entre les ouvertures adjacentes et les pertes de propagation liées à la fabrication sur les performances est aussi étudié en utilisant sur un modèle semi-analytique. Les AWGs communs sont typiquement conçus pour les modes électriques transverses (TE). Pour améliorer la capacité de transmission des réseaux WDM, dans le second chapitre, nous présentons un AWG insensible à la polarisation conçus avec des guides d'onde en SiN. L'insensibilité à la polarisation des AWGs est obtenue lorsque l'espace intercanal et la longueur d'onde centrale des deux modes sont alignés pour un même AWG. L'alignement de l'espace intercanal entre les deux états de polarisations est obtenu en optimisant la géométrie du réseau de guide d'onde, alors que l'insensibilité de la longueur d'onde centrale est obtenue en séparant les deux états de polarisations et en ajustant leur angle d'incidence à l'entrée du coupleur en étoile pour compenser la dispersion entre les modes dans l'AWG. Un multiplexeur de longueur d'onde 1 × 8 avec un espacement entre les canaux de 100 GHz et une diaphonie de −16 dB est démontré expérimentalement. Dans la conception d'un AWGs en SiN, un espacement d'une largeur supérieur à 10 µm entre des guides d'ondes identiques minimise le couplage parasite augmentant ainsi leur empreinte. Dans le troisième chapitre, nous présentons un AWG ultra-compact 1×8 ayant une séparation de 100 GHz entre les canax rendu possible grâce à des guides d'onde en super-réseaux supprimant le couplage entre les guides d'onde. Bénéficiant de la haute densité du super-réseau, cet AWG possède une empreinte compacte de 4.3mm × 0.6mm, ce qui est plus que 2 fois plus petit qu'un AWG conventionnel ayant des performances similaires à celui présenté dans le second chapitre. Le SL-AWG montre aussi une faible perte d'insertion de 3.4 dB et une faible diaphonie de −18 dB. À part le couplage entre les guides d'onde discuté dans le troisième chapitre, l'erreur de phase produite par les variations de fabrication a l'impact le plus important sur les performances de l'AWG. Il a été étudié que leurs performances sont liées à la longueur du réseau de guide d'onde déterminant l'erreur de phase. Toutefois, il existe encore un écart de quantification de l'impact de la longueur du réseau et les variations de fabrication sur les performances de l'AWG. Dans le quatrième chapitre, nous présentons une analyse statistique de l'AWG en présence d'erreurs de phase dans les guides d'onde. Des figures de mérites importantes pour la performance incluant les pertes d'insertion, la diaphonie et la non-uniformité sont paramétrées en fonction de la longueur de cohérence, un paramètre physique qui caractérise l'accumulation d'erreur de phase dans les guides d'ondes optique. Une longueur de cohérence de 23.7 mm au niveau de la matrice pour les guides d'onde de SiN peut être extraite en mesurant les variations dans la longueur d'onde de résonnance d'un interféromètre de Mach-Zhender. Au travers de simulations Monte-Carlo, nous examinons l'impact de l'erreur de phase sur les performances de l'AWG avec une espace entre les canaux de 100 GHz et 200 GHz. / The development of optical communications with high transmission capacity makes wavelength division multiplexing (WDM) systems a hot topic of recent research. In this thesis, we propose and demonstrate arrayed waveguide gratings (AWGs) based on a SiN platform as the multiplexers or demultiplexers. In the first chapter, we compare the material and waveguides between silicon and silicon nitride. We present numerical simulations of the SiN waveguides, including slab waveguides, strip waveguides, bent waveguides and tapered waveguides, using FDTD solutions and MODE solutions from Ansys Lumerical. These waveguides are used to form an AWG in this thesis. The influences of SiN AWGs designed parameters including focal length, separation of arrayed waveguides, gaps between adjacent apertures and propagation loss on the performances are studied based on a semi-analytical model. Common AWGs are typically designed in TE mode. In order to improve the transmission capacity in WDM system, in the second chapter, we present a polarization insensitive AWG built with SiN waveguides. The polarization insensitive AWGs are obtained when both the channel spacing and the center wavelength are aligned for TE and TM modes in a single AWG. The channel spacing polarization insensitivity is obtained by optimizing the geometry of the arrayed waveguides whereas the central wavelength polarization insensitivity is obtained by splitting the two polarization states and adjusting their angle of incidence at the input star coupler. A 100 GHz 1×8 AWG with crosstalk below −16 dB is demonstrated experimentally. In the design of SiN AWGs, the gaps of wider than 10 µm between adjacent identical waveguides are designed to minimize parasitic coupling. However, these gaps suppress further shrinking the footprint of AWGs. In the third chapter, we present an ultra-compact 100 GHz 1 × 8 SiN AWG enabled by a novel concept of the waveguide superlattice suppressing coupling between waveguides. Benefiting from the densely arrayed waveguides patterning with waveguide superlattice, this superlattice AWG has a compact footprint of 4.3 mm × 0.6 mm, which is more than two times smaller than a conventional AWG with similar performance. The SL-AWG also shows a low insertion loss of 3.4 dB and a low crosstalk level of −18 dB. Beside the coupling between waveguides discussed in the third chapter, the phase errors due to fabrication variations have a considerable impact on the performance of AWGs. It is shown that their performances are related to the length of arrayed waveguides determining the phase errors. However, there lacked a practical way to quantify the impact of arrayed waveguide length and fabrication variations on the performances of AWGs. In the fourth chapter, we present a statistical analysis of AWGs in presence of phase errors of arrayed waveguides. The important figures of merits including insertion loss, crosstalk and non-uniformity, are parameterized by the coherence length, a physical parameter that characterizes the accumulated phase errors in an optical waveguide. A die-level coherence length of 23.7 mm for the SiN waveguides is extracted by measuring variation of resonant wavelength of Mach-Zehnder interferometers. Through Monte Carlo simulations, we present the impacts of phase errors on performance of 1 × 4 AWGs with 200 GHz and 100 GHz channel spacings.

Periodic gratings in waveguides act as frequency selective mirrors making them very useful as spectral filters for wavelength division multiplexing applications and as end mirrors for narrow linewidth lasers. A study of the spectral characteristics of both single and double gratings in planar dielectric waveguides is presented. The analysis of light propagation in a planar dielectric waveguide with sinusoidal boundary perturbations is carried out using coupled-mode theory. Power reflection and transmission coefficients are calculated for single gratings as well as two gratings of the same period and depth but arbitrary lengths and separated by a specified distance. The spectral response is examined for several cases. The influence of grating period, depth, and length in the single-grating case as well as separation of the gratings in the case of a double grating is investigated. Numerical results for example cases are presented. The results of this study are valuable for designing grating devices which are becoming increasingly attractive to broadband fiber-optic communication systems. / Master of Science