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 24 for “"grating structures"”.
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Accurate characterization of nanophotonic grating structures
Augmented reality waveguides are designed to have grating regions to in-couple, out-couple, and propagate light from a light engine to the user. This thesis develops two reliable systems to qualify manufactured waveguides. The first system determines grating quality by measuring grating pitch and …
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Advanced fibre Bragg grating structures: design and application
… work on a variety of advanced fibre Bragg grating structures covering long dispersion compensating chirped Bragg gratings, superstructured Bragg gratings for identical multiple channel operation, Bragg gratings for pulse-shaping applications and Bragg gratings for add-drop applications in …
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A coupling-of-modes analysis of SAW grating structures
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981.
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Investigation of fabrication process development for integrated optical grating structures
Sub-micron optical gratings are essential integrated elements to couple light into waveguides and for optical monitoring of microfluidic channels or MEMS devices. Since the required features in the sub-micron regime are difficult to achieve by mechanical ruling and photolithography, alternate …
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Propagation of Leaky Waves in Free Surfaces and Grating Structures on (100)-Cut Gallium-Arsenide
… of propagation of the leaky wave through metal grating structures in $\{$100$\}$-cut GaAs. This objective was met by first understanding wave propagation in free-surface GaAs and subsequently exploring a buried bimetallic electrode structure which will present minimum velocity and impedance …
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Polarization-dependent wavelength-selective structures for multispectral polarimetric infrared imaging
… technology, using CMOS-type metallo-dielectric grating structures, is presented as a potential solution in which the spectral filtering and polarization filtering functions are performed in a single component. In this work, single-layer and double-layer metallic-grating structures, embedded in …
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Electrodeposition of FeCoNiCu quaternary system
… theoretically, for fabrication of multilayers, grating structures, and nanowires. Multilayer structures are composed of alternating ferromagnetic and nonmagnetic nanometric layers, and are of interest due to the giant magnetoresistance (GMR) property it possesses, a change in electric resistance …
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POLYMER–BASED RESONANT WAVEGUIDE GRATING STRUCTURE AND ITS APPLICATIONS
<p>Resonance waveguide grating structures have been a subject of interest for several decades. This optical technique offers unique advantages when compared with other optical components. This stems from their relatively simple structure comprised of layers, as well as their high reflection …
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Subwavelength antireflection and polarization grating elements: Analysis and fabrication
Surface-relief, submicron period transmission gratings are fabricated in fused silica. A rigorous vector diffraction code, based on the coupled-wave analysis technique, is used to design and analyze the surface relief gratings. When light with wavelength greater than the grating period encounters …
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High Extinction Ratio Subwavelength 1D Infrared Polarizer by Nanoimprint Lithography
… stacked 1-dimensional (1-D) subwavelength grating structures were studied to develop compact size IR polarimetric detector by using surface plasmonic polariton. Experimental parameters were optimized by Finite Difference Time Domain (FDTD) simulation. Effects of gold (Au) grating size, …
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Micro- and nano-soft lithography for the fabrication of photonic devices
… and conductive inks to create optically active structures and devices. A series of light emitting polymers (LEPs), blended with a photo-curable host system, have been integrated as colour converters with an array of matrix-addressable gallium nitride (GaN) micro LEDs to form a red-green-blue …
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Templated self-assembly of sub-10 nm quantum dots
… a robust method for the creation of ordered structures at length scales below ten nanometers. The basic process entails creating surface relief templates via electron-beam lithography, and spin-coating a suspension of colloidal nanoparticles onto the template. As the solvent evaporates, the …
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The physics and chemistry of semiconductor nanocrystals in sol-gel derived optical microcavities
… was gleaned from studying these NC-doped sol-gel structures. Chapter 2 describes the synthesis of NC-doped core-shell silica microsphere composites of tunable size and emission wavelength, as well as their subsequent use for in-vivo imaging of blood vessels. This chapter illustrates how an …
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Distributed Feedback Laser Biosensor in Microplate Format
… was used to create subwavelength periodic grating structures, while a horizontal dipping process was used to apply a ~300 nm, dye-doped polymer film. In this work, the DFBLB emission wavelength, used to characterize the device uniformity, demonstrated a coefficient of variation (CV) of …
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Silver (Ag) nanoparticle based masks for the development of antireflection subwavelength structures in GaAs and Si solar cells
… the development of antireflection subwavelength grating (SWG) structures. We particularly investigate the impact of silver thin film thickness and the effect of annealing temperature on the fabrication of silver nanoparticles of controlled size and spacing distributions. We also use these …
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Liquid crystal adaptive planar optical devices
… UV written buried channel waveguide and Bragg grating structures. It has been discovered that the hysteresis seen in previous LC tunable Bragg grating devices is due to a process known as the pincement transition. Pincement involves the transition from a splay-bend wall in the nematic LC to a …
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Integrated through -wafer optical monitoring of MEMS for closed -loop control
… showing a positional resolution of 2 pim using grating structures. Initial binary Fresnel diffractive optical microelement design layout, fabrication parameters, and testing results will be given as well for implementation of a fully integrated optical monitoring system.
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Novel direct UV written devices
… based on UV writing of novel waveguide structures. The first section is an investigation into the production of Direct UV-written channel waveguides on the perimeter of a cylindrical substrate. Cylindrical waveguides were produced using variants of the Modified Chemical Vapour Deposition …
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Integrated chirped Bragg gratings for dispersion control
… for this purpose. A monolithic chirped Bragg grating is presented with dispersion and bandwidth characteristics coinciding with the previously mentioned regimes. The device, based on a deeply etched tapered waveguide design, may be fabricated fully post-growth, lending it a significant …
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Chalcogenide glasses for advanced photonic and photovoltaic applications
… As2Se3 thin film. ChG photonic devices including gratings, waveguides and resonators, can be fabricated using nanoimprint. This technique offers a convenient, high-throughput, and low-cost approach for patterning of sub-micron glass structures. We rationalized the processing design and modified …
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