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 69 for “"Metasurfaces"”.
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Dynamic Metasurfaces for Advanced Applications
<p>To date metamaterials and metasurfaces have been studied for over 20 years. Throughout this time sophisticated understanding of their properties and capabilities has been developed, with many significant and exotic properties such as flat lenses, negative refraction, and perfect absorption. In …
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Design of metasurfaces for detection system application
… Thesis is focused on achieving advances on metasurfaces, which can be integrated in detection systems. The aim is to introduce novel techniques for designing, analyzing, manufacturing and measuring metasurfaces. Firstly, a thorough review of literature contributions on metamaterials is …
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Scaleable nanomanufacturing of metasurfaces using microsphere photolithography
<p>“The cost-effective manufacturing of metasurfaces over large areas is a critical issue that limits their implementations. Microsphere photolithography (MPL) uses a scalable self-assembled microsphere array as an optical element to focus collimated light to nanoscale photonic jets in a …
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Metasurfaces and Their Applications in Photonic Devices
<p>Metasurfaces are flat artificial optical elements composed of dielectric and/or metallic nanostructures. They can manipulate light in unprecedented ways by altering amplitude, phase, and polarization at subwavelength scales. The ability of these two-dimensional elements to perform multiple …
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Dynamic Plasmonic Metasurfaces in the Visible Spectrum
… to keep pushing the boundaries. Plasmonic metasurfaces have been shown to control the phase, amplitude and/or polarisation of incoming electromagnetic radiation. Nano-fabrication advancements have resulted in the fabrication of the building blocks of such metasurfaces at nano-scale …
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Photonic Metasurfaces for Spatiotemporal and Ultrafast Light Control
The emergence of photonic metasurfaces - planar arrays of nano-antennas - has enabled a new paradigm of light control through wave-front engineering. Space-gradient metasurfaces induce spatially varying phase and/or polarization to propagating light. As a consequence, photons propagating through …
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Hybrid metal-dielectric metasurfaces for enhanced optical performance
Metasurfaces are periodic arrays of light scatterers or resonators. The dimensions of these resonators and the spacing between them are smaller than the incident light. Metasurfaces can manipulate the amplitude, phase, and polarisation of the incident light by controlling the resonators’ shape, …
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Scattering design : absorption enhancement and frequency selective metasurfaces
… design method for multi-grid frequency selective metasurfaces based on temporal coupled mode theory (CMT). In particular, we design an elliptic passband filter with a center frequency of 10 GHz, bandwidth of 10% and relatively good angle dependence.
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Design, fabrication, and characterization of optical and photonic metasurfaces
L'abstract è presente nell'allegato / the abstract is in the attachment
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Reconfigurable Intelligent Metasurfaces for Wireless Communication and Sensing Applications
In recent years, metasurfaces have shown promising abilities to control and manipulate electromagnetic (EM) waves through modified surface boundary conditions. These surfaces are electrically thin and comprise an array of spatially varying sub-wavelength scattering elements (or meta-atoms). …
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Anomalous Reflection from Phase Gradient Metasurfaces for Arbitrary Incident Angles
… and narrow frequency bandwidth effectiveness. Metasurfaces are used to address these faults effectively for an array of practical applications. Checkerboard metasurfaces consists of an array of artificial magnetic conductor (AMC) elements, specifically two distinct AMC elements with phase …
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Integral-Equation Modelling of Metasurfaces via the Impedance Boundary Condition
L'abstract è presente nell'allegato / the abstract is in the attachment
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Design and experimental observation of topological states in photonic metasurfaces
… Our convincing results showed that spin-full metasurfaces with Dirac dispersion can potentially serve as a source of arbitrary vector beams for on-chip generation of structured light.</p>
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Reduction Of Mutual Coupling In Antenna Technology Using Elliptically Shaped Metasurfaces
This thesis is devoted to the use of metasurfaces for the goals of the reduction of mutual coupling between closely spaced antennas and the increase of antenna bandwidth. This is done first using a graphene monolayer as a cloak to decrease mutual coupling and restore radiation patterns for closely …
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Analytical Modeling of Waveguide-fed Metasurfaces for Microwave Imaging and Beamforming
… the common approach to model and design such metasurfaces relies on effective surface properties, a methodology that is inspired by initial metamaterial designs. This methodology is only applicable to periodic arrangements of elements, and the assumption that the neighboring elements are …
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Tunable Linear and Nonlinear Metasurfaces Based on Hybrid Gold-Graphene Plasmons
<p>Optical Metasurfaces are planar structures that are patterned with subwavelength structures and are very thin compared to the wavelength of light. Despite their thinness, these structured materials can strongly interact with incident light to effect the functionalities of conventional optical …
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Topological photonic metasurfaces for light manipulation and strong light-matter interaction
… all-dielectric periodic nanostructures (photonic metasurfaces) boost a growth of novel optical technologies, from ultra-sensitive detectors to compact beam structured lasers. Moreover, they represent one of the most promising platforms in which topological phases can be explored and exploited.</p> …
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