Geração, manipulação e caracterização de campos óticos parcialmente coerentes

• Ano de defesa: 2015
• Autor(a) principal: Basso, Gabriel Fernando
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Física; Programa de Pós-Graduação em Física; UFPB
• Palavras-chave em Português: Grau espectral de coerência eletromagnética; Parâmetros de Stokes generalizados; Grau de polarização cruzado; Campo ótico térmico; Intereferômetro HBT; Spectral electromagnetic degree of coherence; Generalized Stokes parameters; Cross-polarization degree; HBT interferometer; CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/5763

In this thesis we address issues pertaining to the fluctuations of the electromagnetic field in the optical domain, both experimentally as well as theoretically and numerically. It was experimentally demonstrated the interdependence between the degree of polarization and the degree of coherence of thermal optical fields. We analyzed the results and explained them in light of a new unifying theory. We have shown a way to control the coerence of light through polarization manipulations, concluding with a proposal for a simple thermal light source with a tunable spectral electromagnetic degree of coherence. We expanded the concept of a tunable light source, suggesting a partially coherent and partially polarized light source with complete control of the so called generalized Stokes parameters by mixing polarized stochastic optical fields. We obtain theoretically the statistical properties of the resulting optical field and their dependence on the properties of the primary fields. We discuss fundamental properties of the mixture of stochastic fields and point out some peculiarities through examples. All results are demonstrated through numerical simulations. We suggest a method to investigate the spatial statistical properties of gaussian stochastic fields through the Hanbury Brown-Twiss (HBT) interferometer, an admittedly simple experimenal method. We show theoretically that it is possible to measure the generalized Stokes parameters, thus allowing one to rebuild the coherence matrix and the polarization matrix of the field, completely characterizing the optical field both statistically and locally in the observation plane. We suggest a technique for the automation of the method, and also some applications. These many studies on the statistical properties of optical fields led us to a deeper understanding of the physical meanings of the parameters for characterizing them. From this understanding we also discuss a change to the definition of the cross-polarization degree and the significance of optical coherence in terms of this new definition.