Recent experimental and theoretical results that link the phenomenon of dielectric relaxation in nematic liquid crystals (NLCs) to their dynamics and fast electro-optical switching are presented. Namely, we illustrate that the dielectric torque acting on the uniaxial nematic liquid crystal depends not only on the present value of the field and the present orientation of the director, but also on the prehistory of these two parameters. The resulting "dielectric memory" effect leads to a spectacular but counter-intuitive effect: director relaxation during the "switch-off" stage can be accelerated if instead of the abrupt vertical back edge, one uses a voltage pulse with a non-instantaneously vanishing back edge. The acceleration effect can be enhanced with a short high voltage pulse at the end of the "switch on" process.

Date Published: 3 February 2009
PDF: 10 pages
Proc. SPIE 7232, Emerging Liquid Crystal Technologies IV, 723206 (3 February 2009); doi: 10.1117/12.811035

Published in SPIE Proceedings Vol. 7232:
Emerging Liquid Crystal Technologies IV
Liang-Chy Chien; Ming Hsien Wu, Editor(s)