Thesis (Ph. D.)--University of Sydney, 2006. / Title from title screen (viewed 30 May 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Physics, Faculty of Science. "Centre for Ultrahigh-bandwidth Devices for Optical Systems" -- T.p. Degree awarded 2006; thesis submitted 2005. Includes bibliographical references. Also available in print form.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2004 / Includes bibliographical references (leaves 83-84)

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 62-68). Also available in electronic version.

Thesis (Ph. D.)--Lehigh University, 2006. / Vita. Includes bibliographical references and vita.

In iron-doped lithium niobate and other similar crystals, exposure to light of appropriate wavelength induces small changes in the refractive index. This phenomenon is called the photorefractive effect. It allows phase holograms to be stored in these crystals. The work to be described was undertaken to obtain a better understanding of the mechanisms of the photorefractive effect and to investigate possible engineering applications. The photorefractive effect is believed to involve the spatial redistribution of photoexcited electrons among traps. This causes a space charge field to develop-which modulates the refractive index via the linear electro-optic effect. A new bulk photovoltaic effect special to ferroelectric crystals, first recognized by Glass et al., is important in the photorefractive effect in these crystals. It is shown that the finite electron transport length in this effect makes the photovoltaic current distribution spatially shifted from the light intensity pattern that causes it. Moreover, it is shown that the spatially varying photovoltaic current component which is responsible for the hologram formation decreases as the spatial frequency of the light interference pattern increases. Hologram writing by the photorefractive effect is modelled for arbitrary electron transport length. The treatment allows for the feedback effect of the space charge field and for the dark conductivity of the crystal. The model applies to uniform illumination and constant applied voltage conditions. It is shown that except in crystals where diffusion dominates the .hologram is spatially shifted from the light intensity pattern that caused it because of the finite electron transport length associated with the bulk photovoltaic effect. Experimental results which bear upon the bulk photovoltaic effect and the associated electron transport length are reported. Hologram writing with an arbitrary one-dimensional light intensity distribution is modelled allowing for the feedback effect of the space charge field at all writing times, A large scale space charge field associated with the envelope of the light is shown to affect the writing process. It is found that for any type of intensity distribution an increase in the fraction of the crystal which is illuminated improves the efficiency of the hologram writing process. Also for partially illuminated crystals the storage efficiency improves as the photoconductivity approaches the dark conductivity value from above. For a fully illuminated crystal the storage efficiency improves as the ratio of the photoconductivity to dark conductivity increases. Experimental observations of the effect of the large scale field on hologram storage are reported. Beam distortion and optically induced scattering are two problems encountered while storing holograms in lithium hipbate. We report experimental observations and theoretical models for these phenomena. It is shown that beam distortion is due to the defocusing action of the large scale refractive index change due to the envelope of light. Light scattering is suggested to be due to the lens action of the index variations due to laser speckles inside the crystal. A theoretical treatment of the spatial filtering properties of volume holograms is presented. Practical applications of volume holograms in the fields of interferometric testing and optical. communications are also discussed. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Unknown

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of doctor of philosophy (Physics) School of Physics. University of the Witwatersrand, Johannesburg. 24 March 2017. / This thesis is an accumulation of the work and that was carried out and published as two articles and two book chapters. Throughout the thesis, we develop and present theoretical as well as numerical model to extend the existing techniques to study the optical properties of photonic crystals, plasmonic photonic crystals and photonic quasicrystals. We start with a background review, where we cover the theoretical aspects of light–matter interaction. That is followed by a review of the physics of photonic crystals. In that chapter, we discuss the different properties of photonic crystals, plasmonic photonic crystals as well as the topic of localization. We then delve into the numerical aspects of the subject. We provide a review on the frequency domain method and the finite–differences–time–domain methods which they are both used in the work to perform different types of simulations. The frequency domain method is, then, extended to enable the numerical analysis of the optical properties in plasmonic photonic crystals. We use first order perturbation theory to study the effect of surface plasmon polaritons on the photonic band structure of plasmonic photonic crystals. We developed a simple numerical tool that extends the standard frequency domain methods to compute the photonic band structure of plasmonic photonic crystals. We then employ the two stage cut and project scheme to generate a dodecagonal two–dimensional quasiperiodic structure. The finite-differences-time–domain method is applied to simulate the propagation of electromagnetic modes in the system. We compute the transmission coefficients as well as the inverse participation ratio for a quasicrystal consisting of dielectric cylindrical rods. The analysis has shown that crystal has critical states. Furthermore, we apply the frequency domain method to quantify the localized modes in the vicinity of defects in a two–dimensional photonic crystal. We compute the intensity of those modes in the surroundings of the defects sites to identify their nature. Finally, we use the finite–differences–time–domain method to provide a second example of a quasicrystalline structure, where the states are localized. / GR2018

Graduation date: 1994

Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, Centre for Micro-Photonics, 2008. / Submitted for the degree of Doctor of Philosophy, Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, 2008. Typescript. Bibliography: p. 104-118.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 55-57).

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007. / Smith, Glenn, Committee Member ; Trebino, Rick, Committee Member ; Adibi, Ali, Committee Chair ; Gaylord, Thomas, Committee Member ; Buck, John, Committee Member.