Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 118 for “"Optical response"”.
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Optical Response Of Finite And Extended Systems
We developed a method for the calculation of the optical response of infinite systems within time dependent density functional theory. The use of a linear combination of local orbitals and the explicit evolution of the system in time are the main characteristics of our method. It was implemented …
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FABRICATION AND OPTICAL RESPONSE OF SILVER NANOWIRE METAMATERIALS
… they can potentially provide in designing the optical response of a material. Engineering of the electromagnetic subunits means that the optical constants of a fabricated medium are not restricted to the limits encountered in nature. Metamaterials operational at visible frequencies require …
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Interlayer optical response of yttrium barium (copper (cobalt, zinc)) oxide
We report optical reflectance and spectroscopic ellipsometry measurements of the in- and out-of-plane dielectric responses of chain substituted $\rm YBa\sb2Cu\sb3O\sb{6 + x}$ and $\rm YBa\sb2(Cu\sb{1 - y}Co\sb{y})\sb3O\sb{6 + x}$ and of plane substituted $\rm YBa\sb2(Cu\sb{1 - y}Zn\sb{y})\sb3O\sb{6 …
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Nonlinear Optical Response of Simple Molecules and Two-Photon Semiconductor Lasers
… white-light continuum generation, all-optical switching, and nonlinear spectroscopy. In this work the nonlinear dynamics of molecules are investigated in both liquid and gas phase with the recently developed beam deflection technique which measures nonlinear refraction directly in the …
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Tunable organization of cellulose nanocrystals for controlled thermal and optical response
… control and fine tuning of thermal and optical properties based on a proper understanding of their individual behavior and interactions at different length scales. In the present work, we attempt to provide an integral description of the influence of single crystals in the thermal and …
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Theoretical and experimental assessment of the optical response of planar microlens arrays
… to develop a theoretical method to estimate the optical properties and response of a homogenous, apposition microlens array. While other similar studies of microlens arrays have been performed, none were found to determine the total field of view, overlap in the field of view nor the estimated …
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The Self-Assembly, Optical Response and Stretch Tunability of Plasmonic Nanoparticle Monolayers
The optical properties of self-assembled plasmonic nanoparticle monolayers of varying den sities are explored. These particles are sensitive to changes in their local environment and proximity to other particles. By altering these factors, the appearance of nanoparticle assemblies is changed, …
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Coupling of the electrical, mechanical and optical response in polymer/liquid-crystal composites
… droplets embedded in a polymer matrix may enable optical switching in the composite film through the alignment of the LC director along an external electric field. When a ferroelectric material is used as host polymer, the electric field generated by the piezoelectric effect can orient the …
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Exploring the Structural and Optical Response of Halide Perovskites Using High-Energy Electrons
… of cathodoluminescence (CL-SEM) to probe the optical properties of halide perovskites at the nanoscale, and the development of strategies to push the limits of 4D-STEM towards *in-situ* and *operando* conditions. The study demonstrates that high-energy electron probes are a powerful tool for …
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Peculiar perovskites: Unraveling the unique optical response of hybrid organic-inorganic perovskites from first principles
… including solar cells, light-emitting diodes, optical detectors, and spintronics due to their unique atomic, electronic, and optical properties. HOPs and LHOPs are hosts to fascinating microscopic interactions that influence their macroscopic optical and electronic properties. Researchers still …
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Electric Field Manipulation of Gold Nanorods: Characterization of Far-Field Alignment and Spatial Positioning Through Optical Response Imaging Techniques
… nanoparticles in order to take advantage of optical and electrical properties resulting from plasmonic oscillations in addition to increasing the mechanical toughness of the polymer. The ability to create long range patterns in the nanophase will significantly enhance these applications.</p> …
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Dynamical effects in crystalline solid state systems: theory of temperature dependent optical response of bulk gaAs and vibrational modification of C(111) 2 x 1 Surface in Comparison to Experiment
… applied and demonstrated for the linear optical response of bulk gallium arsenide and electronic structure of the C(111) 2 x 1 surface. Both cases are complimented by comparison of key observables to experimental data which may be used to judge the quality of the results. The results are …
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Temperature dependent structural, electronic and optical properties of the Si(100) surface from first principles
… a harmonic and anharmonic approach, and the optical response of the Si bulk and Si(100) surface calculating the temperature dependent reflectance anisotropy (RA). The surface reconstruction and temperature stimulated dimer flip impacts the surface reconstruction dynamics, the surface band gap …
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Studies Of Liquid Crystal Response Time
In this dissertation, the response time issue of the liquid crystal (LC) devices is investigated in meeting the challenges for display and photonic applications. The correlation between the LC director response time and the optical response time is derived theoretically and confirmed …
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First-principles investigations of transition metal hyperdoped silicon and germanium for intermediate band engineering
… solar spectrum. Additionally, if the photoresponse of silicon could be extended to the infrared, silicon could be used to replace more expensive germanium based detectors. My thesis research focuses on defect engineering of silicon to extend the photoresponse to the infrared regime. …
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Plasma-Assisted Molecular Beam Epitaxial Growth of Indium Nitride for Future Device Fabrication
… nucleation densities. Characterization of the optical response of InN films was performed using Fourier transform spectroscopy. Trends in the structural periodicity and optical response were found and are presented within.</p>
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Functional nanostructured plasmonic materials: fabrication, simulation, imaging and sensing applications
… plasmonic materials with predictable optical properties. A novel, low-cost optical sensor with atomic scale sensitivity at visible wavelength range was developed by tuning the optical response of a plasmonic crystal to visible wavelengths through optimization of the distribution and …
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Utilisation of Cellulose Nanocrystals for the Fabrication of Photonic Materials
… with periodic nanostructures. The same striking optical response can be obtained artificially by structuring materials on the same length scale. As an example, naturally derived cellulose nanocrystals (CNCs) can be self-assembled to form a helicoidal nanostructured film that displays vivid …
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The interplay between order and disorder in cholesteric hydroxypropyl cellulose films
… toolkit (PyLlama) was developed to model the optical response of arbitrary multilayer stacks, and applied to the specific case of a monodomain cholesteric liquid crystal. These results were combined with a statistical method (Monte Carlo) that simulates the penetration of light inside …
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