Polarization Optics of Periodic Media

The thesis describes different approaches for the simulation of light propagation in anisotropic media. It will focus, especially, on polarization effects in anisotropic media with periodic structure. The work gives shortly a theoretical background with some essential considerations for polarization optics. This includes Maxwell's equations, the explanation of matrix concepts for optical elements and a mathematical discussion concerning the conditions for a possible separation of problems for two particular orthogonal polarizations. Methods for the simulation of light propagation with application examples for each method are described. The introduced methods will be used to analyze periodic or quasi-periodic structures. The 4x4 matrix method is used for the investigation of the reflection behaviour of cholesteric liquid crystals. Expanding this method by statistical means to inhomogeneous liquid crystals such as polymer-dispersed liquid crystals are investigated. Moreover, a special optimization method for cholesteric Bragg filters is proposed. A space-grid time-domain method is presented and applied to liquid crystal gratings, for which the director configurations are calculated explicitly. The last chapter deals with special phases of chiral nematic liquid crystals: the Blue Phases. The diffraction effects of Blue Phase structures are examined applying a 4x4 matrix method. The method was extended to be applicable to anisotropic crystal problems. The polarization and interference effects are described. Finally, Mueller matrices of the light, which is Bragg reflected by the Blue Phase structures, are calculated and compared with published experimental values for the some components of the Mueller matrices. Additionally, experimental aspects like preparation, polymerization and measurements of Blue Phases are presented and evaluated

Thèse de doctorat : Université de Neuchâtel : 2004 ; 1749