Efeitos da codopagem de Yb3+ nas propriedades espectroscóspicas de vidros fosfatos dopados com Er3+ para aplicações em telecomunicações

• Ano de defesa: 2018
• Autor(a) principal: Vieira, Janielma Karine dos Santos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Alagoas; Brasil; Programa de Pós-Graduação em Física; UFAL
• Palavras-chave em Português: Absorção da luz; Luminescência; Amplificadores ópticos; Teoria de Judd-Ofelt (Espectroscopia); Light Absorption; Luminescence; Optical amplification; Theory of Judd-Ofelt (Spectroscopy); CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA
• Link de acesso: http://www.repositorio.ufal.br/handle/riufal/4604

In this work we investigated the spectroscopic properties of the PZABP vitreous system doped with Er3+/Yb3+. All samples have composition 60P2O5-15 ZnO-5Al2O3-10BaO-10PbO in mol%, and were doped with 1.0% by weight with Er2O3 and coded with Yb2O3 in the concentration ranging from 0.0-2.5% by weight, in order to analyze possible structural changes in the matrix. These glasses were produced by the melting / cooling method. The samples were characterized with measures of absorbance, luminescence and life time in order to investigate the variations that occur for several matrix compositions. The optical window determined by absorption spectroscopy is between 250 and 3000 nm. Absorption spectra showed that the Gap and Urbach energy decreased as we increased the concentration of Yb3+. This result was attributed to the increased hygroscopy of the sample. The analysis based on the Judd-Ofelt theory was made from the absorption spectra of the individualized bands. The determination of the phenomenological parameters, such as radiative life time, luminescence quantum efficiency and branching ratio, also showed little change in the crystal lattice structure. The variation of the Judd-Ofelt parameters indicated that the mean radius of the rare earth ligand ion decreased by creating a redistribution of the electron density when the concentration of the Yb3 + ion increases. The concentration variation showed for the density measurements a small fluctuation, which was already expected due to the glass manufacturing process. The refractive index had a similar result, where the result obtained is in agreement with the results found in the literature. A relationship between refractive index and density showed that the dominant effect occurred through changes in polarizability. Emission spectroscopy was used and the luminescence life time was studied, where it was observed that it was not affected by concentration quenching effects of the luminescence suppression. The results obtained contribute with research on materials that can be used as active means for optical amplification in devices doped with rare earths.