Thesis (M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographical references.

Thesis (M.Eng.). / Written for the Dept. of Electrical and Computer Engineering. Title from title page of PDF (viewed 2008/04/12). Includes bibliographical references.

Thesis (M. S.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2008. / Committee Chair: El-Sayed, Mostafa A.; Committee Member: Lyon, L. Andrew; Committee Member: Sherrill, C. David; Committee Member: Wang, Zhong Lin; Committee Member: Whetten, Robert L.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 80-92). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Oregon, 2005. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 166-173). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 278-288).

abstract: This thesis summarizes the research work carried out on design, modeling and simulation of semiconductor nanophotonic devices. The research includes design of nanowire (NW) lasers, modeling of active plasmonic waveguides, design of plasmonic nano-lasers, and design of all-semiconductor plasmonic systems. For the NW part, a comparative study of electrical injection in the longitudinal p-i-n and coaxial p-n core-shell NWs was performed. It is found that high density carriers can be efficiently injected into and confined in the core-shell structure. The required bias voltage and doping concentrations in the core-shell structure are smaller than those in the longitudinal p-i-n structure. A new device structure with core-shell configuration at the p and n contact regions for electrically driven single NW laser was proposed. Through a comprehensive design trade-off between threshold gain and threshold voltage, room temperature lasing has been proved in the laser with low threshold current and large output efficiency. For the plasmonic part, the propagation of surface plasmon polariton (SPP) in a metal-semiconductor-metal structure where semiconductor is highly excited to have an optical gain was investigated. It is shown that near the resonance the SPP mode experiences an unexpected giant modal gain that is 1000 times of the material gain in the semiconductor and the corresponding confinement factor is as high as 105. The physical origin of the giant modal gain is the slowing down of the average energy propagation in the structure. Secondly, SPP modes lasing in a metal-insulator-semiconductor multi-layer structure was investigated. It is shown that the lasing threshold can be reduced by structural optimization. A specific design example was optimized using AlGaAs/GaAs/AlGaAs single quantum well sandwiched between silver layers. This cavity has a physical volume of 1.5×10-4 λ03 which is the smallest nanolaser reported so far. Finally, the all-semiconductor based plasmonics was studied. It is found that InAs is superior to other common semiconductors for plasmonic application in mid-infrared range. A plasmonic system made of InAs, GaSb and AlSb layers, consisting of a plasmonic source, waveguide and detector was proposed. This on-chip integrated system is realizable in a single epitaxial growth process. / Dissertation/Thesis / Ph.D. Electrical Engineering 2012

xiii, 133 p. ; ill. (some col.) A print copy of this title is available through the UO Libraries. Search the library catalog for the location and call number. / We analyze the effect of geometry and surface morphology on the optical properties of metal-dielectric systems. Using both analytical and numerical modeling, we study how surface curvature affects the propagation of surface plasmon polaritons (SPPs) along a metal-dielectric interface. We provide an intuitive explanation for how the curvature causes the phase front to distort, causing the SPPs to radiate their energy away from the metal-dielectric interface. We quantify the propagation efficiency as functions of the radius of curvature, and show that it depends nonmonotonically on the bend radius. We also show how the surface morphology influences the transmittance and the reflectance of light from disordered metal-dielectric nanocomposite films. The films consist of semicontinuous silver films of various surface coverage that are chemically deposited onto glass substrates. They exhibit a large and broadband reflection asymmetry in the visible spectral range. In order to investigate how the surface morphology affects the asymmetry, we anneal the samples at various temperatures to induce changes in the morphology, and observe changes in the reflection spectra. Our study indicates that the surface roughness and the metal surface coverage are the key geometric parameters affecting the reflection spectra, and reveals that the large asymmetry is due to the different surface roughness light encounters when incident from different side of the film. Additionally, we analyze how thin metal and dielectric layers affect the optical properties of metal-dielectric systems. Using the concept of dispersion engineering, we show that a metal-dielectric-metal microsphere--a metal sphere coated with a thin dielectric shell, followed by a metal shell--support a band of surface plasmon resonances (SPRs) with nearly identical frequencies. A large number of modes belonging to this band can be excited simultaneously by a plane wave, and hence enhancing the absorption cross-section. We also find that the enhanced absorption is accompanied by a plasmon assisted transparency due to an avoided crossing of dominant SPR bands. We demonstrate numerically that both the enhanced absorption and the plasmon assisted transparency are tunable over the entire visible range. We also present an experimental study of light scattering from silica spheres coated with thin semicontinuous silver shells, and attempt to describe their optical response using a modified scaling theory. This dissertation includes previously published co-authored materials. / Adviser: Miriam Deutsch

xiii, 129 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Surface plasmon polaritons (SPPs) are collective electron excitations with attendant electromagnetic fields which propagate on a metal-dielectric interface. They behave, in many ways, as model two-dimensional electromagnetic waves. However, because the evanescent field of the SPPs extends a short distance outside the interface, a near-field probe can modify the wave propagation. We use this behavior to study both SPP scattering within the plane of the interface and also the transition to free-space propagation out of the plane. We have, in particular, studied the multiple scattering of SPPs excited on rough silver films. Our laboratory possesses apertureless near-field scanning optical microscopes (A-NSOMs), the probes of which can act as an in-plane scatterer of SPPs. Subsequent momentum-conserving decays of the SPPs generate an expanding hollow cone of light to which information about the direction and phase of the SPPs on the surface is transferred. A focus of our studies has been SPP multiple scattering when one of the scatterers (the tip) can move. This problem is very closely related to a similar problem in mesoscopic electronic transport, involving "universal conductance fluctuations". It is also related to various radar-detection, microwave communications and medical imaging problems. In parallel with actual experimental measurements, we have also conducted extensive Monte Carlo simulations of the scattering. Multiple scattering leads to the appearance and detection of "speckle" in the far field. A speckle field, however, is more properly considered in terms of its embedded optical vortices and so we have used holographic techniques to study these. We have demonstrated that vortices can be manipulated, created and destroyed by movement of the STM probe tip. Optical vortices are an example of the effect of "geometric" or "topological" phase in physics and as such link the trajectory of a parameter in one space to the phase observed in another. In our case, the trajectory of the A-NSOM tip parallel to the sample surface plane generates topological phase in the far field, manifestations of which are vortices. / Committee in charge: Stephen Kevan, Chairperson, Physics; Stephen Gregory, Advisor, Physics; Michael Raymer, Member, Physics; David Strom, Member, Physics; Mark Lonergan, Outside Member, Chemistry

Made available in DSpace on 2014-06-11T19:29:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-06Bitstream added on 2014-06-13T18:38:54Z : No. of bitstreams: 1 klein_is_me_araiq.pdf: 1781422 bytes, checksum: 6f5028c57d1a8baefe1e772753ae105c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Vidros no sistema binário NaPO3-WO3 vem despertando intenso interesse acadêmico e tecnológico devido as suas propriedades ópticas promissoras tais como fotocromismo, termocromismo e eletrocromismo, bem como altos índices de refração não-lineares. Contudo, um estudo de inclusão de nanopartículas metálicas nestes vidros ainda não foi desenvolvido, o que poderia potencializar as suas aplicações já conhecidas. Neste trabalho, foram obtidos vidros no sistema NaPO3-WO3-Ag2O, em que a concentração de óxido de tungstênio foi mantida fixa a 50% em mol, e variou-se a concentração de prata. A presença das nanopartículas de Ag em vidros submetidos a tratamento térmico foi confirmada por Microscopia Eletrônica de Transmissão, em que foi obtido o tamanho médio das partículas em função da concentração de Ag. No sistema estudado, foi confirmada a presença das unidades estruturais constituintes do sistema binário NaPO3-WO3, utilizando-se diversas técnicas espectroscópicas. A coloração dos vidros depende da concentração de prata incluída no sistema, em que as concentrações mais baixas (5-10% em mol) apresentam coloração vermelha, e em vidros contendo 12,5 a 20% em mols do metal apresentam coloração amarela. A fim de elucidar as diferenças entre estes domínios de concentração e coloração, diversas espectroscopias foram utilizadas, incluido Espectroscopia de Fotoelétrons induzida por raios- X (XPS), a qual permitiu concluir que todas as amostras possuem apenas tungstênio no seu estado mais oxidado (W+6), estando apenas “parcialmente” reduzido pela influência da prata nas amostras. Sugere-se que as diferenças entre os vidros então se devam principalmente na influência das ressonâncias de plasmon apresentadas pelas nanopartículas metálicas, sendo estas confirmadas por Espectroscopia Eletrônica na região do UV-Vis. / Glasses in binary system NaPO3-WO3 are of great interest due to its promising optical properties, such as photochromism, thermochromism and electrochromism, as well as high non-linear refraction index. However, a study concerning metallic nanoparticle inclusion into these glasses has not been reported yet. In this work, glasses in the system NaPO3-WO3-Ag2O were prepared keeping tungsten oxide concentration constant at 50% mol concentration rate and varying silver concentration. Glass samples submitted to adequate thermal treatment shown the presence of Ag nanoparticles confirmed by Transmission Electron Microscopy, which allowed to determine nanoparticle average size versus Ag concentration. In this system, the constituting structural units of the binary system NaPO3-WO3 were confirmed by several spectroscopic techniques. The coloration of glasses is directly correlated to silver concentration, showing a red color at lower amount of silver (5-10% mol) and yellowish for silver concentration in the range from 12.5 to 20% mol. To understand this behavior, several spectroscopy techniques were used, including X-Ray Photoelectron Spectroscopy (XPS), indicating the presence of tungsten only in its most oxidized form (W+6) been only “partially” reduced by the influence of silver. We suggest that the difference between the glasses arise mostly on plasmon resonance of the metallic nanoparticles, confirmed by UV-Vis Electronic Spectroscopy.