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Title: Photorefractivity in polymer-stabilized nematic liquid crystals

Technical Report ·
DOI:https://doi.org/10.2172/656737· OSTI ID:656737
 [1];  [1]
  1. Argonne National Lab., IL (United States). Chemistry Div.

Polymer-stabilized liquid crystals, consisting of low concentrations of a polymeric electron acceptor, are shown to exhibit significantly enhanced photorefractive properties. The charge generation and transport properties of these composite systems are strongly modified from nematic liquid crystals doped with electron donors and acceptors. The new composites are produced by polymerizing a small quantity of a 1,4:5,8-naphthalenediimide electron acceptor functionalized with an acrylate group in an aligned nematic liquid crystal. Photopolymerization creates an anisotropic gel-like medium in which the liquid crystal is free to reorient in the presence of a space charge field, while maintaining charge trapping sites in the polymerized regions of the material. The presence of these trapping sites results in the observation of longer lived, higher resolution holographic gratings in the polymer-stabilized liquid crystals than observed in nematic liquid crystals alone. These gratings display Bragg regime diffraction. Asymmetric beam coupling, photo-conductivity, and four-wave mixing experiments are performed to characterize the photophysics of these novel materials.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Energy Research, Washington, DC (United States)
DOE Contract Number:
W-31109-ENG-38
OSTI ID:
656737
Report Number(s):
ANL/CHM/CP-96854; CONF-980731-; ON: DE98057787; TRN: AHC29817%%295
Resource Relation:
Conference: 43. international symposium on optical science, engineering, and instrumentation, San Diego, CA (United States), 19-24 Jul 1998; Other Information: PBD: [1998]
Country of Publication:
United States
Language:
English