Accession Number:

ADA361351

Title:

Electroclinic Liquid Crystal Materials for Electrooptic Imaging

Descriptive Note:

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR BIOMOLECULAR SCIENCE AND ENGINEERING

Report Date:

1993-01-01

Pagination or Media Count:

5.0

Abstract:

The correlation between molecular structure and electrooptic performance is studied for two series of ferroelectric liquid crystalline materials. The first series Series 1 consist of siloxy units attached to the hydrocarbon chain at the non-chiral end of the molecule while the second series Series 2 contain only hydrocarbon chains at the end of the molecule. Series 1 exhibit chiral smectic A SmA and smectic C SmC. It is observed that slight modifications in either the siloxy or the hydrocarbon chain length has strong effect on the electrooptic properties. Increasing the number of siloxy unit in the chain Series 1 increases the temperature range of SmA, and reduces the SmA-SmC transition temperature. All materials have melting temperatures below room temperature, and exhibit high values of induced tilt angles. In Series 2, the materials show a broad SmA temperature range, and melting temperatures much higher than in Series 1. However, the SmA phase is found to supercool to subambient temperatures. If the hydrocarbon chain is shortened, tilt angle, electroclinic coefficient and switching time are significantly suppressed. Comparison of the electrooptic performance in SmA between the two series show that Series 1 show a much higher tilt angles than Series 2, while the later exhibit much faster response times.

Subject Categories:

  • Electricity and Magnetism
  • Optics
  • Electrooptical and Optoelectronic Devices

Distribution Statement:

APPROVED FOR PUBLIC RELEASE