Thesis (Ph.D.) -- McMaster University, 2002. / Letter in title is Greek letter [mu]. Includes bibliographical references (leaves 135-142). Also available via World Wide Web.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: FDTD; Linear interpolation; MEMS; NEMS; Photonic crystals; Wavelength conversion; Frequency conversion; Doppler. Includes bibliographical references (leaves 107-114).

Thesis (M. App. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 73-78). Also available in electronic format on the Internet.

Thesis (Ph.D.) - Carleton University, 2006. / Includes bibliographical references (p. 91-100). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Ray T. Chen. Vita. Includes bibliographical references.

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed on September 12, 2006). PDF text of dissertation: 149 p. : ill. ; 0.72Mb. UMI publication number: AAT 3209965. Includes bibliographical references. Also available in microfilm and microfiche format.

Long-wavelength magnetic anomalies (LWMA) are broad scale magnetic fields that are usually observed at satellite altitudes. The origin of these fields have been assumed to be solely from the crust, disregarding possible contributions from the upper mantle. Using data from magnetic mantle xenoliths, the possible mantle contribution to LWMA was investigated for different regions including Siberian craton, Kamchatka subduction zone fore-arc, Hawaii hotspot, and French Massif Central plume. To do this, a MATLAB-based forward-modeling of magnetic anomalies from tectonic regions with different upper mantle geotherms and magnetized mantle geometries was developed. This model incorporated the increase in Curie temperature of magnetite with pressure, the current geotherms of the specific regions, and the statistical distributions of magnetic data from xenoliths in the specific regions. A Monte-Carlo method of random selection of values and repeated calculations was utilized in constraining the range of potential mantle contributions to satellite-observable LWMA. The Siberian craton shows the highest possible contribution to satellite magnetic anomalies with amplitudes ranging from 2 nT to 9 nT, with a wavelength equivalent to the long-axis of the craton. The Hawaii hotspot region displays a significant contribution of its upper mantle to satellite measured magnetic anomalies with an amplitude of the order of 2 nT, while the Massif Central plume regions shows an insignificant contribution of its upper mantle to satellite magnetic anomalies with potential total magnetic anomaly amplitude of 0.07 nT. Finally, the mantle portion of Kamchatka subduction zone shows a sizeable contribution to magnetic anomalies measurable at satellite altitude with an amplitude up to 1.3 nT. These results when compared with lithospheric total field intensity model derived from SWARM satellite data, show that the upper mantle can contribute significantly to LWMA depending on (a) the average remanent magnetization in xenoliths from such regions, (b) the thickness of magnetized mantle, and (c) the size of the region under consideration.

abstract: Nanolasers represents the research frontier in both the areas of photonics and nanotechnology for its interesting properties in low dimension physics, its appealing prospects in integrated photonics, and other on-chip applications. In this thesis, I present my research work on fabrication and characterization of a new type of nanolasers: metallic cavity nanolasers. The last ten years witnessed a dramatic paradigm shift from pure dielectric cavity to metallic cavity in the research of nanolasers. By using low loss metals such as silver, which is highly reflective at near infrared, light can be confined in an ultra small cavity or waveguide with sub-wavelength dimensions, thus enabling sub-wavelength cavity lasers. Based on this idea, I fabricated two different kinds of metallic cavity nanolasers with rectangular and circular geometries with InGaAs as the gain material and silver as the metallic shell. The lasing wavelength is around 1.55 μm, intended for optical communication applications. Continuous wave (CW) lasing at cryogenic temperature under current injection was achieved on devices with a deep sub-wavelength physical cavity volume smaller than 0.2 λ3. Improving device fabrication process is one of the main challenges in the development of metallic cavity nanolasers due to its ultra-small size. With improved fabrication process and device design, CW lasing at room temperature was demonstrated as well on a sub-wavelength rectangular device with a physical cavity volume of 0.67 λ3. Experiments verified that a small circular nanolasers supporting TE¬01 mode can generate an azimuthal polarized laser beam, providing a compact such source under electrical injection. Sources with such polarizations could have many special applications. Study of digital modulation of circular nanolasers showed that laser noise is an important factor that will affect the data rate of the nanolaser when used as the light source in optical interconnects. For future development, improving device fabrication processes is required to improve device performance. In addition, techniques need to be developed to realize nanolaser/Si waveguide integration. In essence, resolving these two critical issues will finally pave the way for these nanolasers to be used in various practical applications. / Dissertation/Thesis / Ph.D. Electrical Engineering 2014

Made available in DSpace on 2016-03-15T19:37:40Z (GMT). No. of bitstreams: 1 Palmerston Donizzeti Taveira.pdf: 3709250 bytes, checksum: f7776004371e059d73f0d20c8d735c07 (MD5) Previous issue date: 2006-08-02 / The optical amplifier has improved the optical communication systems because they lead to an increase in transmission capacity of medium and long haul optical systems, with technological advantages over electronic regenerators. The optical amplifier are relatively simple to deploy and can be used in optical links without any troubles regarding signal transmission rate improvement and signal modulation changes, as a consequence of these issues they can substitute the electronic regenerator enhancing security with low operation cost. The CWDM systems multiplex optical wavelength with a low cost in metropolitan networks. It was developed to connect backbone networks to metro core and edge networks with cost saving over DWDM systems but lower transmission capacity. We have developed and characterized in our research a discrete Raman amplifier for operation in O band. We connected the amplifier in a point to point CWDM in order to analyze the gain on the system transmission capacity and the impairments that appears in the system. Working with a eight channel CWDM in O band, modulated with 2.5 Gbit/s, we have demonstrated that we can use a discrete Raman amplifier in single configurations, pre amplifier, booster and line amplifier and shared configuration with booster and pre amplifier to increase the transmission capacity that means, increase the length of the optical link. We have increased in 110% the length of the optical link with a shared configuration of two amplifiers with 10 dB gain for each one. / Os amplificadores ópticos revolucionaram a tecnológica das comunicações ópticas, pois possibilitaram o aumento da capacidade de transmissão dos sistemas ópticos de média e longa distância, com vantagens tecnológicas sobre os regeneradores. Estes dispositivos são relativamente simples de serem desenvolvidos, utilizam poucos componentes e podem ser utilizados nas redes ópticas de forma transparente a taxa de transmissão e modulação do sinal. Substituem assim, com vantagens, os regeneradores eletrônicos, agregando segurança e baixo custo à operação das redes ópticas. Os sistemas CWDM realizam a multiplexação óptica de comprimentos de onda a um baixo custo em redes metropolitanas. São utilizados para conectar as redes de transporte de alta capacidade às redes de acesso, trazendo uma larga vantagem em custo sobre os sistemas DWDM, porém com menor capacidade de transmissão. Nosso trabalho de pesquisa consistiu em desenvolver e caracterizar um amplificador Raman discreto na banda O (1260 a 1360 nm), aplicando este amplificador em um sistema CWDM ponto a ponto com taxa de transmissão de 2.5 Gbit/s por canal e analisando o aumento na capacidade de transmissão e os efeitos que degradam o sinal transmitido. Trabalhando com um sistema CWDM com oito canais na banda O, demonstramos que podemos utilizar um amplificador Raman discreto nas configurações isoladas de pré-amplificador, booster e amplificador de linha e na configuração simultânea de booster e pré-amplificador para aumentar a capacidade de transmissão. Aumentamos o comprimento original do enlace em 110%.