Title page for etd-0708114-141107


[Back to Results | New Search]

URN etd-0708114-141107
Author Yi-Jen Tzou
Author's Email Address No Public.
Statistics This thesis had been viewed 5351 times. Download 0 times.
Department Electro-Optical Engineering
Year 2013
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Study of polarization-independent gratings based on polymer-stabilized optically isotropic liquid crystals
Date of Defense 2014-07-15
Page Count 87
Keyword
  • polarization independent
  • azobenzene
  • phase grating
  • polymer stabilized isotropic phase
  • polymer stabilized blue phase
  • monomer
  • Liquid crystal
  • Abstract This thesis discusses the electro-optical properties of polymer-stabilized optically isotropic liquid crystal (PSILC) phase gratings. In the first part of the study, PSILC precursors were formulated by by doping green-light initiator and curable monomers into a blue phase liquid crystal. Polymer stabilization process was conducted by interfering two coherent green lasers onto PSILC samples and thus produced spatially periodic polymer network. Dense and thin polymer fibers were formed under strong irradiation, while their loose and thick counterparts were polymerized in those low-intensity areas. Different polymer textures offer different anchoring forces. Thereby, when an electric field activates the phase grating, the probe sees a periodically varying refractive index and is thereby diffracted. The second section presents improved phase gratings using azobenzene-doped PSILCs. By means of holographic green illumination, the dye-doped liquid crystal in the bright regions transited isothermally to the isotropic phase from the blue phase whereas that in the dark remained the same. In such gratings, index only changes in the blue phase liquid crystal regions as an electric field is applied. It is worth noting that the optical isotropy of the proposed gratings results in polarization-independent diffractions. Furthermore, both kinds of the PSILC gratings response on the sub-millisecond scale.
    Advisory Committee
  • Fuh, Andy Y.G. - chair
  • Wei Lee - co-chair
  • Kuang-Yao Lo - co-chair
  • Chi-Yen Huang - co-chair
  • Tsung-Hsien Lin - advisor
  • Files
  • etd-0708114-141107.pdf
  • Indicate in-campus at 99 year and off-campus access at 99 year.
    Date of Submission 2014-08-08

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys