| spelling |
Carlos Henrique Monkenhttp://lattes.cnpq.br/0398657255645016Larissa VertchenkoLuiz Gustavo de Oliveira Lopes CançadoLeonardo Teixeira Neveshttp://lattes.cnpq.br/7163695412216209Rodrigo Silva Amorim2023-02-27T14:52:36Z2023-02-27T14:52:36Z2023-02-09http://hdl.handle.net/1843/50432As q-plates são placas de onda capazes de transformar o estado de polarização e a frente de onda da luz. A orientação do eixo rápido de uma q-plate varia ao longo de sua seção transversal possibilitando a geração de feixes de luz com momento angular orbital e que possuem polarização não homogênea, os chamados feixes vetoriais. O objetivo desta dissertação é apresentar a caracterização de placas q-plates, fornecidas por colaboradores da Universidade Técnica da Dinamarca, constituídas de nano-pilares de silício amorfo, distribuídos periodicamente, no intuito de gerar o fenômeno de birrefringência de forma. Mostramos, teoricamente, os mecanismos de funcionamento das q-plates que permitem a geração de todos os feixes vetoriais presentes na esfera de Poincaré de ordem superior, uma representação geométrica que engloba os perfis espaciais e o estado de polarização desses tipos de feixes. Visando caracterizar as placas produzidas, realizamos experimentos capazes de mostrar a geração dos feixes vetoriais e dos modos Laguerre-Gaussianos, conhecidos por possuírem momento angular orbital. Para os feixes vetoriais, analisamos o perfil de intensidade do feixe após atravessar um polarizador. Foi possível notar que o perfil se altera, mostrando o caráter não homogêneo do estado de polarização. No caso dos feixes com momento angular orbital, suas frentes de onda apresentam uma forma helicoidal, por isso usamos um interferômetro de Mach-Zhender para fazer sua análise. Na saída do interferômetro, obtivemos um padrão de interferência em formato de pétalas, característicos dos feixes helicoidais. Com isso, concluímosQ-plates are wave plates capable of transforming the polarization state and wavefront of light. The orientation of the fast axis of a q-plate varies along its cross section enabling the generation of light beams with orbital angular momentum and that have inhomogeneous polarization, the so-called vector beams. The goal of this dissertation is to present the characterization of q-plates, provided by collaborators from the Technical University of Denmark, composed of amorphous silicon nanopillars, periodically distributed, in order to generate the phenomenon of form birefringence. We theoretically show the functioning mechanisms of the q-plates that allow the generation of all vector beams present on the higher order Poincaré sphere, a geometric representation that encompasses the spatial profiles and the polarization state of these types of beams. To characterize the produced plates, we conducted experiments that could show vector beam generation and Laguerre-Gaussian modes known for its orbital angular momentum. For vector beams, we have analyzed the intensity profile of the beam after crossing a polarizer. It was possible to notice that the profile changes, showing the inhomogeneous character of the polarization state. In the case of beams with orbital angular momentum, their wavefronts have a helical shape, so we used a Mach-Zhender interferometer to analyze them. At the output of the interferometer, we obtained an interference pattern in the shape of petals, characteristic of helical beams. Hence, we conclude that the manufactured q-plates can generate the theoretically predicted transformations.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorporUniversidade Federal de Minas GeraisPrograma de Pós-Graduação em FísicaUFMGBrasilICX - DEPARTAMENTO DE FÍSICAÓpticaMomentos angularesFeixes vetoriaisQ-plateFeixes vetoriaisBirrefringência de formaMomento angular orbitalDesenvolvimento e caracterização de q-plates: geração de feixes helicoidais e vetoriaisDevelopment and characterization of q-plates: formation of helical and vector beamsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALDissertação Versão final Rodrigo Silva Amorim.pdfDissertação Versão final Rodrigo Silva Amorim.pdfDissertaçãoapplication/pdf23336905https://repositorio.ufmg.br/bitstream/1843/50432/3/Disserta%c3%a7%c3%a3o%20Vers%c3%a3o%20final%20Rodrigo%20Silva%20Amorim.pdfd7d74d41c20bddcc7fe011593bdae2b3MD53LICENSElicense.txtlicense.txttext/plain; charset=utf-82118https://repositorio.ufmg.br/bitstream/1843/50432/4/license.txtcda590c95a0b51b4d15f60c9642ca272MD541843/504322023-02-27 11:52:37.628oai:repositorio.ufmg.br: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ório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2023-02-27T14:52:37Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
|