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Now showing items 1-10 of 10

  • Coexisting Nematic and Smectic- A Phases in a Twisted Liquid-Crystal Cell 

    Ruan, Lizhen; Osipov, M. A.; Sambles, J. Roy (American Physical Society, 2001)
    Twisted homogeneously planar-aligned nematic liquid-crystal cells are cooled into the smectic- A phase. The expected defective structure does not form. Instead the cells still show good optical-guiding characteristics. ...
  • Coupled surface plasmons and optical guided wave exploration of near-surface director profile 

    Yang, Fuzi; Ruan, Lizhen; Jewell, Sharon A.; Sambles, J. Roy (Institute of Physics and Deutsche Physikalische Gesellschaft, 2007)
    For a liquid crystal (LC) cell with thin silver claddings it is possible, using a high index coupling prism, to excite both surface plasmon modes and ordinary optical guided modes. In a situation where the tilt of the ...
  • Delay effect of switch-on in a supertwisted nematic cell 

    Yang, Fuzi; Dong, Youmei; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2004)
    By using a convergent beam system and the fully leaky guided mode technique the switch-on dynamics of an 180° supertwisted nematic have been studied. Using the Ericksen–Leslie theory and analyzing the guided mode data taken ...
  • Dynamical process of switch-off in a supertwisted nematic cell 

    Yang, Fuzi; Dong, Youmei; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2004)
    The switch-off dynamics of a 180° supertwisted nematic (STN) are explored in detail by using a convergent beam system and the fully leaky guided-mode technique. From the dynamical guided-mode data and using the Ericksen–Leslie ...
  • Exploration of the surface director profile in a liquid crystal cell using coupling between the surface plasmon and half-leaky optical guided modes 

    Yang, Fuzi; Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2008)
    The half-leaky guided mode geometry with a thin metal tunnel barrier as one cladding layer is used to explore the distribution of the director very near to the surface in a hybrid aligning nematic liquid crystal cell. From ...
  • Flow-Induced Twist-Compression in a Twisted Nematic Cell 

    Ruan, Lizhen; Sambles, J. Roy (American Physical Society, 2003)
    An optical convergent-beam guided-wave technique is used to explore in detail the dynamic flow effects in a twisted nematic cell. During switch-on it is found that the dynamic flow compresses the director twist to regions ...
  • Leaky-wave exploration of two-stage switch-on in a nematic pi-cell 

    Ruan, Lizhen; Sambles, J. Roy (American Institute of Physics, 2005)
    The two-stage switch-on dynamics of a nematic pi-cell are explored in detail using a convergent beam fully-leaky guided mode technique. The cell shows an initial switch-on with a time scale in the range several ms to tens ...
  • Otto-coupled surface plasmons in a liquid crystal cell 

    Ruan, Lizhen; Yang, Fuzi; Sambles, J. Roy (American Institute of Physics, 2009)
    Surface plasmons on silver in the visible domain are excited using a several micron thick layer of liquid crystal as the optical tunnel barrier. This thickness is possible when the orientation of the director in the liquid ...
  • Self-Organized Periodic Photonic Structure in a Nonchiral Liquid Crystal 

    Ruan, Lizhen; Sambles, J. Roy; Stewart, I. W. (American Physical Society, 2003)
    A hybrid-aligned cell of the smectic A liquid material 8CB gives two stable director configurations, one of which is periodic and gives strong diffraction of light. This photonic lattice director profile arises from ...
  • Voltage dependent director of a homeotropic negative liquid crystal cell 

    Ruan, Lizhen; Yang, Fuzi; Sambles, J. Roy (American Institute of Physics, 2008)
    Thin layers of obliquely (60° to normal) thermally evaporated SiOx lead to homeotropic alignment of a nematic liquid crystal (LC) having negative dielectric anisotropy. Under application of an ac voltage the director, as ...