<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:METS="http://www.loc.gov/METS/" xmlns:fits="http://hul.harvard.edu/ois/xml/ns/fits/fits_output" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:IR="http://dl.lib.brown.edu/md/irdata" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:rights="http://cosimo.stanford.edu/sdr/metsrights/" ID="etd86">
     <mods:titleInfo>
      <mods:title>Photo-Patterning Studies for Liquid Crystal Alignment</mods:title>
     </mods:titleInfo>
     <mods:name type="personal">
      <mods:namePart>Eakin, James Nelson</mods:namePart>
      <mods:role>
       <mods:roleTerm type="text">creator</mods:roleTerm>
      </mods:role>
     </mods:name>
     <mods:originInfo>
      <mods:copyrightDate keyDate="yes" encoding="w3cdtf">2008</mods:copyrightDate>
     </mods:originInfo>
     <mods:physicalDescription>
      <mods:extent>xxiv, 169 p.</mods:extent>
      <mods:digitalOrigin>born digital</mods:digitalOrigin>
     </mods:physicalDescription>
     <mods:note>Thesis (Ph.D.) -- Brown University (2008)</mods:note>
     <mods:name type="personal">
      <mods:namePart>Crawford, Gregory</mods:namePart>
      <mods:role>
       <mods:roleTerm type="text">director</mods:roleTerm>
      </mods:role>
     </mods:name>
     <mods:name type="personal">
      <mods:namePart>Hurt, Robert</mods:namePart>
      <mods:role>
       <mods:roleTerm type="text">reader</mods:roleTerm>
      </mods:role>
     </mods:name>
     <mods:name type="personal">
      <mods:namePart>Zaslavsky, Alexander</mods:namePart>
      <mods:role>
       <mods:roleTerm type="text">reader</mods:roleTerm>
      </mods:role>
     </mods:name>
     <mods:name type="corporate">
      <mods:namePart>Brown University. Division of Engineering. Electrical Sciences and Computer Engineering</mods:namePart>
      <mods:role>
       <mods:roleTerm type="text">sponsor</mods:roleTerm>
      </mods:role>
     </mods:name>
     <mods:genre authority="aat">theses</mods:genre>
     <mods:abstract>This dissertation utilizes holographic exposure techniques to manipulate the periodic orientation of liquid crystal materials. Two different exposure techniques are investigated: a
      polarization holography interference method incident on a photo-responsive surface to induce a preferential ordering, and an amplitude holography interference method that relies on a phase
      separation and counter-diffusion reaction to create stratified regions of liquid crystal and polymer. In the phase holography investigations, a linear photopolymerizable (LPP) layer is
      selectively polymerized permanently capturing phase information from the interference patterning and transferring it to align a liquid crystal material. The underlying periodic and frustrated
      alignment in the one- and two-dimensional alignment configurations is discussed, including the nature of their electro-optic switching transitions. A phenomenological model is presented to
      describe the Freedericksz transition, or lack thereof, for the registered planar-periodic boundary conditions resulting from the interference of two orthogonal circularly polarized beams. In the
      amplitude holography investigations, the frustrated chiral and smectic ordering of ferroelectric liquid crystal domains encapsulated by a polymer binder were established. The refractive index
      modulation in these thin films is modeled as a phase grating that can be electrically addressed to erase the optical diffractive properties. A phenomenological model is developed to take into
      account a distribution of domain sizes and an effective field that stabilizes the ferroelectric liquid crystal domains. A diffraction model successfully predicts changes in normalized
      intensities for first-order diffraction with applied field. These gratings demonstrate microsecond-scale response and relaxation times for various grating pitch sizes between 3 and 12
      micrometers.</mods:abstract>
     <mods:subject authority="local">
      <mods:topic>alignment</mods:topic>
     </mods:subject>
     <mods:subject authority="local">
      <mods:topic>surface ordering</mods:topic>
     </mods:subject>
     <mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/999541"><mods:topic>Liquid crystals</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1070588"><mods:topic>Polymers</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/893514"><mods:topic>Diffraction</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1046845"><mods:topic>Optics</mods:topic></mods:subject><mods:recordInfo>
      <mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource>
      <mods:recordCreationDate encoding="iso8601">20091218</mods:recordCreationDate>
     </mods:recordInfo>
    <mods:language><mods:languageTerm type="code" authority="iso639-2b">eng</mods:languageTerm><mods:languageTerm type="text">English</mods:languageTerm></mods:language><mods:identifier type="doi">10.7301/Z0P8496Z</mods:identifier><mods:accessCondition type="rights statement" xlink:href="http://rightsstatements.org/vocab/InC/1.0/">In Copyright</mods:accessCondition><mods:accessCondition type="restriction on access">Collection is open for research.</mods:accessCondition><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource></mods:mods>