Reflection Spectra of Distorted Cholesteric Liquid Crystal Structures in Cells with Interdigitated Electrodes (Postprint)

Abstract

We studied the appearance of second- and third-order Bragg reflections in cholesteric liquid crystals (CLCs) in cells where the electric field was perpendicular to the helical axis. Second-order reflections with reflectance values as large as 80% of the first-order one were observed in the gap regions of alignment cells with interdigitated electrodes for CLC mixtures with pitches in the range 0.5-1.0 microns upon application of a field. The characterization was enabled by local probing of the CLC using a microspectrophotometer. LC cells that are transparent in the visible spectrum in the off-state and become colored upon application of a field due the second- or third-order reflection band appearance were demonstrated. The spectral position of the higher-order Bragg reflections can also be tuned by adjusting the magnitude of the electric field.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2014
Accession Number
ADA614813

Entities

People

  • Mariacristina Rumi
  • Timothy J. Bunning
  • Timothy White

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Crystal Structure
  • Crystals
  • Detectors
  • Diffraction
  • Electric Fields
  • Electrodes
  • Liquid Crystals
  • Magnetic Fields
  • Optical Properties
  • Optics
  • Physical Properties
  • Reflectance
  • Reflection
  • Refractive Index
  • Spectra

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Optical Physics and Photonics.