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 153 for “"Optical devices"”.
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Voltage programmable liquid optical devices
… at two types of voltage programmable liquid optical device. The first is a rotatable liquid crystal waveplate and the second is an amplitude programmable liquid phase grating. The rotatable waveplate was created by confining a droplet of E7 nematic liquid crystal between two glass substrates …
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Liquid crystal adaptive planar optical devices
… based on using liquid crystals (LC) with planar optical lightwave components. Adaptive optical devices have been fabricated by combining LCs with direct UV written buried channel waveguide and Bragg grating structures. It has been discovered that the hysteresis seen in previous LC tunable Bragg …
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Opto-VLSI processing for reconfigurable optical devices
… of Wavelength Division Multiplexing system (WDM) optical fibre transmission systems has the potential to realise this high capacity data rate exceeding 10 Tb/s. The ability to reconfigure optical networks is a desirable attribute for future metro applications where light paths can be set up or …
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Voltage induced spreading and liquid optical devices
An experimental investigation has been carried out into Liquid dielectrophoresis (LDEP), in which dielectric forces are used to actuate bulk liquid spreading and to imprint a deformation pattern at a liquid air surface. Our basic conguration uses a set of co-planar stripe interdigital electrodes to …
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Interference lithography for optical devices and coatings
… defect-free nanostructures with unique optical properties. In this thesis, interference lithography will be utilized to create photonic crystals for functional devices or coatings. For instance, typical lithographic processing techniques were used to create 1, 2 and 3 dimensional …
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In-fiber Optical Devices Based on D-fiber
… the fabrication and analysis of in-fiber devices based on elliptical core D-shaped optical fiber. Devices created inside optical fibers are attractive for a variety of reasons including low loss, high efficiency, self-alignment, light weight, multiplexibility, and resistance to …
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Noise Suppression in OCDMA Networks using Nonlinear Optical Devices
Optical code division multiple access (OCDMA) is a multiplexing technique that has a number of inherent advantages that make it suitable for use in passive optical networks, such as allowing subscribers to transmit information in an asynchronous fashion over a single optical fibre. This form of …
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Finite difference time domain simulation of subpicosecond semiconductor optical devices
… method to simulate a subpicosecond semiconductor optical switch is developed in this research. The problem under studying involves both electromagnetic wave propagation and semiconductor dynamic transport, which is a nonlinear phenomenon. Finite difference time domain (FDTD) technique is used to …
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Strain-tuning of periodic optical devices : tunable gratings and photonic crystals
The advancement of micro- and nano-scale optical devices has heralded micromirrors, semiconductor micro- and nano-lasers, and photonic crystals, among many. Broadly defined with the field of microphotonics and microelectromechanical systems, these innovations have targeted applications in …
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Polarizing Optical Devices Based on Embedded One-Dimensional Subwavelength-Structured Photonic-Crystal Layers
Quarter-wave retarders (QWR) that employ total internal reflection (TIR) and interference of light in a transparent thin-film coating at the base of a prism are presented. Explicit equations that guide the optimal design are provided. The optimal refractive index and normalized thickness of QWR …
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On-chip Group and Phase Velocity Control for Classical and Quantum Optical Devices
… an emphasis on two-dimensional photonic crystal devices in this thesis. We describe the theory, analytical and numerical designs, and experimental characterization of silicon nanophotonic devices both in classical and quantum space. These devices which include negatively refractive photonic …
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Temperature and Spatial Hole Burning Effects in Semiconductor Lasers and Integrated Optical Devices
… long-wavelength InP-based lasers and integrated optical devices, including Fabry-Perot (FP) lasers, distributed-feedback (DFB) lasers, and integrated electroabsorption modulator with DFB lasers (EML). First, the temperature dependence of bulk InGaAsP semiconductor laser diodes is analyzed using a …
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A study of novel mid-infrared optical devices: Wave plates and tunable filters
… sensing and thermal imaging. However, many optical devices that are common in the visible range are not as accessible in the mid-infrared. In this thesis, we look to partially address this problem by proposing two novel structures using subwavelength gratings. First, we look at a wave plate …
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Development of electrical and optical devices for next generation high-speed optical interconnects
… IoT are pushing data traffic toward >1.6 Tb/s optical links with much lower energy per bit. VCSEL based multichannel transceivers are one of the most cost- and power-efficient choice for short-reach interconnects, but further scaling is limited by modal dispersion in multimode VCSELs and …
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Development of X-ray lithography and nanofabrication techniques for III-V optical devices
… techniques for Bragg-grating-based integrated optical devices in III-V materials. Work on this rich family of devices has largely been limited to numerical analysis because of the difficulties of their fabrication. The challenges of fabrication are addressed by dividing the problem along two …
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Integration of III-V optical devices and interconnects on Si using SiGe virtual substrates
… promise for the combination of electrical and optical devices onto a Si platform. Monolithic integration, compare to hybrid integration, is the more cost effective and reliable way to combine these dissimilar materials. However, materials compatibility issues such as lattice mismatch, …
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Iterative nonlinear beam propagation method and its application in nonlinear devices
… propagation method is introduced and applied to optical devices. This method is based on Hamiltonian ray tracing and the Wigner distribution function. First, wave propagation simulation using Hamiltonian ray tracing is illustrated and verified with different examples. Based on this, the iterative …
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The Lady Showroom: Optical Representations in the Works of Joanna Baillie and Louisa Stuart Costello
… visually through textual description, use of optical devices, and discussion of bodies and appearances. This thesis argues that they were trying to see and show other women as a way of understanding themselves and each other by examining intersections between visual culture and text through …
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Modified chalcogenide glasses for optical device applications
… examined and their potential for use as active optical materials is explored. It is also argued that the spectroscopic analysis of transition metal ions is a useful tool for evaluating the local environment of their host. Secondly femtosecond (fs) laser modification of GLS is investigated as a …
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Use of aluminum bearing III-V semiconductor native oxides for optical and current confinement in waveguides and lasers
Data are presented on various laser and optical devices that utilize native oxidation of Al bearing III-V semiconductors to effect large lateral index steps. These large index steps are due to the low refractive index of the Al bearing native oxide (n $\sim$ 1.5), making possible the fabrication of …
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