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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 93 for “"Lithium Niobate"”.
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Novel devices in periodically poled lithium niobate
… out to develop several novel periodically poled lithium niobate (PPLN) devices. These devices exploit the ability to invert micro-domains of spontaneous polarisation in ferroelectrics such as lithium niobate. <br/><br/>The fabrication of PPLN devices is described and extensive studies into …
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Domain engineering techniques and devices in lithium niobate
… to domain engineering single-crystal congruent lithium niobate at the micron/sub-micron scale for practical device applications. <br/><br/>Experimental etch-rate measurements from a parametric study of etch-rates and etch-quality of single-crystal lithium niobate z-faces, as a function of …
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K-band lithium niobate microelectromechanical system hybrid filters
As the sub-6G spectrum becomes overcrowded with applications, the research community has begun to explore beyond 6 GHz for new spectral venues to advance wireless capabilities. Acoustic filters are indispensable front-end components in telecommunication, which is challenging to scale to higher …
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Super-high-frequency lithium niobate microelectromechanical system resonators
… (A1) mode in ion-sliced and suspended Z-cut lithium niobate (LiNbO3) thin films, which feature a phase velocity exceeding 10,000 m/s. The fabricated device has demonstrated a high electromechanical coupling (kt2) of 29% and a high quality factor (Q) of 527 simultaneously. Hence, this work …
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Laser-assisted surface and domain microstructuring of lithium niobate
… of investigations into the nano-structuring of lithium niobate using the combined or sequential action of laser light and a chemical etch (a mixture of hydrofluoric and nitric acids). Novel methods to characterise ferroelectric domains using Raman spectroscopy and surface second harmonic …
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FABRICATION METHODOLOGIES FOR INTEGRATED PHOTONIC DEVICES IN LITHIUM NIOBATE
Lithium niobate is one of the most commonly used materials in the active photonic devices. However, the fabrication of advanced LiNbO3 devices like suspended membrane is still quit challenging, limiting the development of integrated optics. The overall aim of this study was to explore the …
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Lithium niobate thin films on diamond substrates for SAW devices
Lithium niobate thin films have been grown on diamond/silicon substrates by metallo-organic decomposition and radio frequency (R. F.) magnetron sputtering. The surface acoustic wave (SAW) characterizations of the multilayer lithium niobate/diamond/silicon are calculated. The lithium niobate thin …
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An experimental study of proton-exchanged lithium niobate optical waveguides
… gives a brief introduction to the properties of lithium niobate, and discusses the methods available for fabricating optical waveguides in the bulk material, with particular emphasis on waveguide fabrication by the proton-exchange process. Some of the devices which have been fabricated by …
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Lithium niobate RF-MEMS oscillators for IoT, 5G and beyond
… focuses on the design and implementation of lithium niobate (LiNbO3) radiofrequency microelectromechanical (RF-MEMS) oscillators for internet-of-things (IoT), 5G and beyond. The dissertation focuses on solving two main problems found nowadays in most of the published works: the narrow tuning …
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Light-induced ferroelectric domain engineering in lithium niobate & lithium tantalate
… on ferroelectric domain engineering in lithium niobate and lithium tantalate is investigated. The conventional method of domain inversion is electric field poling, which suffers from several limitations such as a requirement for photolithography and high-voltage equipment, the formation …
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Direct UV writing of structures in lithium niobate and lithium tantalate
… fabrication of UV direct write structures in lithium niobate and lithium tantalate. Unassisted direct writing of surface channel waveguides using lambda = 244 nm cw light resulted in polarisation specific waveguides fabricated on z- cut crystals. Waveguides were characterised using mode …
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Frequency-resolved optical gating in periodically-poled lithium niobate waveguide devices
… first successful implementation of an integrated Lithium Niobate for the FROG device, based on sum-frequency generation. We demonstrated simultaneous complete characterisation of two ultrashort pulses of durations 4-25 ps in the 1.55 µm-band with a coupled energy of 430 fJ in a 26mm long PPLN …
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Fabrication and applications of zinc indiffused waveguides in periodically poled lithium niobate
… channel waveguides in periodically poled lithium niobate (PPLN) is reported in this thesis. The thesis covers all stages from the production of PPLN by domain inversion on a micron scale through to optical testing. The factors affecting poling quality, such as crystal discrepancies from …
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Interactions of single-crystal lithium niobate surfaces with ultra-violet laser radiation
… of ultraviolet laser light on single crystal lithium niobate surfaces with a focus on useful functionalisation. The investigations split naturally into three areas: effects on hydrophilicity by low intensity laser irradiation, effects on ferroelectric domain inversion by focussed laser …
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Processing and characterization of lithium niobate thin films for ferroelectric nonvolatile memory applications
Both highly c-axis and randomly-oriented LiNbO3 thin films are grown on p-type Si (111) substrates by RF magnetron sputtering and metallo-organic decomposition (MOD), respectively. Ellipsometry, X-ray diffraction, AFM and SEM are used to analyze the structural quality of the deposited ferroelectric …
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Electrical characterizations of lithium niobate thin films in a metal-ferroelectric-semiconductor capacitor
A LiNbO3 thin film Metal-Ferroelectric-Semiconductor capacitor is analyzed with various electrical characterization methods for studying the polarization switching and the thin film conduction behavior. The polarization density vs. electric field (P-E) curve shows that the remnant polarization is …
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Chemical evolution, heteroepitaxy, and monolayer patterning of solution-derived lithium niobate thin layers
Integrated lithium niobate (LiNbO$\sb3$) thin films are of technical interest for frequency doubling and a variety of efficient photonic circuit element applications. Solution deposition of such films on near lattice-matched substrates has been conducted, allowing low temperature processing, …
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All-optical signal processing using cascaded quadratic interactions in periodically poled lithium niobate waveguides
… quadratic nonlinearities in periodically poled lithium niobate (PPLN) waveguides for telecommunication applications. PPLN waveguides which possess high second-order nonlinearity are attractive due to their suitable properties with respect to high compactness, high operating speed and resistance …
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Microstructuring and domain-engineering of lithium niobate using combinations of light, etching and poling
… thesis reports methods for microstructuring of lithium niobate. The process of light induced frustrating etching, where light from a laser is used to inhibit the etching of iron doped lithium niobate, is the subject of a detailed investigation so a better understanding of the process can be …
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