Investigação das propriedades ópticas não-lineares de cristais líquidos esméticos dopados com nanobastões de ouro

• Autor(a) principal: Silva, Ricardo Santos
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal de Alagoas (UFAL)
• Texto Completo: http://www.repositorio.ufal.br/handle/riufal/1728
• topic: Física; Óptica não-linear; Cristais líquidos; Nonopartículas de ouro; Physic; Nonlinear optics; Liquid crystals; Gold nanoparticles; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

The present work is devoted to the study of the nonlinear optical properties of smectic samples containing gold nanoparticles with a rod shape. By using the time-resolved Z-scan technique, we determine the nonlinear refractive and absorptive coefficients at the vicinity of the smectic-A-nematic phase transition. Our results reveal that such coefficients are sensitive to the sample temperature. In particular, we show that the nonlinear refractive index presents a singular behavior close to the transition temperature. Further, we show that a nonlinear optical response may take place at temperatures where the smectic order is well established. We provide a detailed discussion of the effects associated with the introduction gold nanoparticles on the mechanisms behind the optical nonlinearity in liquid-crystal samples.