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dc.contributor.advisorSarid, Droren_US
dc.contributor.authorGIBBONS, WAYNE MICHAEL.
dc.creatorGIBBONS, WAYNE MICHAEL.en_US
dc.date.accessioned2011-10-31T17:02:00Z
dc.date.available2011-10-31T17:02:00Z
dc.date.issued1987en_US
dc.identifier.urihttp://hdl.handle.net/10150/184212
dc.description.abstractThe properties of all-optical nonlinear waveguide devices are investigated. In particular, the nonlinear directional coupler (NLDC) and nonlinear Mach-Zehnder interferometer (NLMZ) are analyzed using perturbation theory. The perturbation theory provides differential equations that describe the amplitude of the waveguide modes as a function of the propagation distance. To be practical, these waveguide devices require nonlinear phase shifts of π or more. Therefore, the theoretical investigation of these devices emphasizes their fabrication in bulk and multiple-quantum-well (MQW) gallium arsenide (GaAs). For the first time, absorption, carrier diffusion, and thermal effects are included in the theoretical investigation of the NLMZ and NLDC. The nonlinear dependence of the coupling terms, which has been neglected in all previous work, is shown to be significant for semiconductor based NLDC's. The effects of carrier diffusion on the nonlinear response of a GaAs waveguide is demonstrated using a self-consistent numerical method. The effects are heavily dependent on the waveguide geometry, and, therefore, should be included in the analysis of nonlinear semiconductor waveguide devices. However, if the diffusion length is large compared to the mode width, carrier diffusion simplifies the investigation since the nonlinear absorption and index change are uniform across the mode. This important conclusion is used in the models for the NLMZ and NLDC. The theoretical models predict the NLMZ and NLDC should work in bulk and MQW GaAs. To demonstrate that the required nonlinear phase shifts for the NLMZ and NLDC are indeed possible in bulk and MQW GaAs, the first experimental observation of electronic optical bistability in a MQW GaAs strip-loaded waveguide is recounted. This original research illustrated that phase shifts in excess of 2π are possible in MQW GaAs waveguides and, therefore, the future of all-optical waveguide devices in semiconductors is optimistic.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectOptical wave guides.en_US
dc.subjectDirectional couplers.en_US
dc.subjectInterferometers.en_US
dc.titleALL-OPTICAL NONLINEAR WAVEGUIDE DEVICES.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.identifier.oclc699819538en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest8727926en_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-06-17T17:40:12Z
html.description.abstractThe properties of all-optical nonlinear waveguide devices are investigated. In particular, the nonlinear directional coupler (NLDC) and nonlinear Mach-Zehnder interferometer (NLMZ) are analyzed using perturbation theory. The perturbation theory provides differential equations that describe the amplitude of the waveguide modes as a function of the propagation distance. To be practical, these waveguide devices require nonlinear phase shifts of π or more. Therefore, the theoretical investigation of these devices emphasizes their fabrication in bulk and multiple-quantum-well (MQW) gallium arsenide (GaAs). For the first time, absorption, carrier diffusion, and thermal effects are included in the theoretical investigation of the NLMZ and NLDC. The nonlinear dependence of the coupling terms, which has been neglected in all previous work, is shown to be significant for semiconductor based NLDC's. The effects of carrier diffusion on the nonlinear response of a GaAs waveguide is demonstrated using a self-consistent numerical method. The effects are heavily dependent on the waveguide geometry, and, therefore, should be included in the analysis of nonlinear semiconductor waveguide devices. However, if the diffusion length is large compared to the mode width, carrier diffusion simplifies the investigation since the nonlinear absorption and index change are uniform across the mode. This important conclusion is used in the models for the NLMZ and NLDC. The theoretical models predict the NLMZ and NLDC should work in bulk and MQW GaAs. To demonstrate that the required nonlinear phase shifts for the NLMZ and NLDC are indeed possible in bulk and MQW GaAs, the first experimental observation of electronic optical bistability in a MQW GaAs strip-loaded waveguide is recounted. This original research illustrated that phase shifts in excess of 2π are possible in MQW GaAs waveguides and, therefore, the future of all-optical waveguide devices in semiconductors is optimistic.


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