Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514430
Title: Forward and inverse problem for nematic liquid crystals
Author: Al-Humaidi, Saleh
Awarding Body: The University of Manchester
Current Institution: University of Manchester
Date of Award: 2010
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Abstract:
This thesis starts with an introduction to liquid crystal properties, which are needed to proceed with this research. From the dielectric tensor which appears in the Maxwell equations, we were able to obtain a relationship between the elements on the main diagonal of the dielectric tensor. This relationship has been discussed and illustrated with some examples for both positive and negative birefringence. By introducing a constrain on the Berreman model, we were able to derive a 2x 2 differential equation in matrix form which works for both normal and oblique incidence. This equation gives us a simple and intuitive means to analyze the evolution of light through all sorts of media ie. isotropic, anisotropic with a fixed transmission axis and anisotropic with a twisted transmission axis of anisotropy. One of the objectives of this research was to find the right technique to solve the 2 x 2 dynamic equation. Fortunately, the classic Floquet's theory guarantees the existence of the solution and it gives some of its characteristics. In fact, we were able to solvethe 2x 2 Schrodinger equation by a new method which we called it in this thesis a rotational frame method. The obtained solution is consistent with Floquet's theory and agrees totally with the Jones solutions. Also, this solution allows us to test the Berreman approximation. Finally, in this research we were able to encode the orientation of the optical axis inside a liquid crystal sample, into the potential of the Schrodinger equation. As a consequence of that, solving the inverse problem of the Schrodinger equation that is recovering the potential, is indeed recovering the orientation of the director inside the sample. The Berreman inverse problem and its corresponding linearized problem has been considered in this thesis. In these sections, we give a rigorous derivation for the Frechet derivative.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.514430  DOI: Not available
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