Produção e caracterização de guias de ondas óticos em fluoreto de lítio

• Ano de defesa: 2012
• Autor(a) principal: Chiamenti, Ismael
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Tecnológica Federal do Paraná; Curitiba; Programa de Pós-Graduação em Engenharia Elétrica e Informática Industrial
• Palavras-chave em Português: Guias de ondas ópticos; Fluoreto de lítio - Propriedades ópticas; Centros de cor; Guias de ondas; Redes de Bragg; Engenharia elétrica; Optical wave guides; Lithium fluoride - Optical properties; Color centers; Wave guides; Bragg gratings; Electric engineering
• Link de acesso: http://repositorio.utfpr.edu.br/jspui/handle/1/392

This work describes the production and characterization of optical waveguides in lithium fluoride crystal (LiF) produced by exposing the crystal to a focused femtosecond laser beam, with the crystal displacement perpendicular to the beam. The measured emissions, with specific illumination, demonstrate the presence of color centers of types F2 and F+3 at the crystal regions exposed to the focused laser beam. The produced structures have increased refractive index relative to the crystal refraction index. Such structures are characterized in terms of their morphology using conventional and confocal microscopy. Their ability to guide light is investigated through coupling different laser light. The propagation modes supported by the guides are also estimated, as well as the propagation losses. The production of a Bragg grating waveguide is locked for by coupling a white light in the guides and comparing its spectrum with that passing only through the crystal. The guiding capacity of the structural changes produced is confirmed by the near-field profile analysis. The guides support few propagation modes and the obtained changes in the refractive index are in the order of 10^-4.