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Opto-Electronics Review

Editor-in-Chief: Jaroszewicz, Leszek

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1896-3757
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Volume 21, Issue 2

Issues

Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

G. Derfel / M. Buczkowska
Published Online: 2013-03-15 | DOI: https://doi.org/10.2478/s11772-013-0083-9

Abstract

Deformations of homeotropically aligned flexoelectric nematic layers induced by dc electric fields were simulated numerically. Two different anchoring strengths on the limiting surfaces were assumed. Nematic material was characterised by negative dielectric anisotropy. Both signs of the sum of flexoelectric coefficients were taken into account. The electric properties of the layer were described in terms of a weak electrolyte model. Mobility of cations was assumed to be one order of magnitude lower than that of anions. Quasi-blocking electrode contacts were assumed. The threshold voltages for deformations were determined by means of calculations of the phase difference Φ between ordinary and extraordinary light rays passing through a layer placed between crossed polarisers. The threshold values depended on the polarity of the bias voltage U. When the threshold value was exceeded, the phase difference increased with the voltage. Two different Φ(U/Uthreshold) dependencies for the two polarities of the voltage were found for each layer if the nematic possessed the flexoelectric properties. The possibility of using this effect to detect the flexoelectricity in the nematic was explored by simulated experiments. The effectiveness of the proposed method is discussed.

Keywords: nematics; flexoelectricity; director deformations; optical retardation; surface anchoring

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About the article

Published Online: 2013-03-15

Published in Print: 2013-06-01


Citation Information: Opto-Electronics Review, Volume 21, Issue 2, Pages 205–209, ISSN (Online) 1896-3757, DOI: https://doi.org/10.2478/s11772-013-0083-9.

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© 2013 SEP, Warsaw. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. BY-NC-ND 3.0

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