Modos ressonantes em filmes de cristais líquidos colestéricos contendo deformações Gaussianas no Pitch

• Autor(a) principal: Silva, Rafael Rocha da
• Data de Publicação: 2010
• 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/4751
• topic: Óptica de cristal; Cristais colestéricos; Cristais líquidos; Crystal optics; Cholesteric crystals; Liquid Crystals; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

In this work, We use Berreman’s Matrix method to obtain the reflection and transmission coefficients in a cholesteric liquid crystal film containing structural defects. In particular, We investigated how a Gaussian pitch profile affects the optical properties of cholesteric films. Our results show that a pair of defect modes emerges inside the bandgap as modulation width is increased. In addition, We observe that the reflection spectrum of cholesteric systems exhibits a strong dependence on the parameters of the Gaussian profile, such as the amplitude and the Center position. The effects associated with the insertion of multiple Gaussian deffects have been also studied and the chromaticity diagram hás been computed. Our results demonstrate that a Gaussian pitch profile is excellent alternative to generate and tune defect modes, with a potential application in the design of new eletro-optical devices based on cholesteric systems