Surface Azimuthal Anchoring Energy between the Grating Surface and Nematic Liquid Crystal Layer Studied by Finite Element Method

2004 ◽  
Vol 43 (7A) ◽  
pp. 4310-4311 ◽  
Author(s):  
Yasuyuki Ohta ◽  
Norihiko Tanaka ◽  
Munehiro Kimura ◽  
Tadashi Akahane
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Nematic Liquid Crystal Layer ◽  
Anchoring Energy ◽  
Azimuthal Anchoring Energy ◽  
Element Method

SURFACE AZIMUTHAL ANCHORING ENERGY BETWEEN THE GRATING SURFACE AND NEMATIC LIQUID CRYSTAL LAYER STUDIED BY USING A GEOMETRIC MODEL

2017 ◽  
Vol 41 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Chin-Lung Lin ◽  
Tei-Chen Chen
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Geometric Model ◽  
Model Parameters ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Nematic Liquid Crystal Layer ◽  
Anchoring Energy ◽  
Good Agreement ◽  
Azimuthal Anchoring Energy

A simple geometric model is proposed for estimating the azimuthal anchoring energy between the sinusoidal relief grating surface and nematic liquid crystal layer of a liquid crystal display (LCD) device as a function of the grating height and grating pitch. The model parameters are determined experimentally, and the model is then used to predict the surface azimuthal anchoring energy for gratings with various pitches and heights. It is shown that a good agreement exists between the predicted results for the surface azimuthal anchoring energy and the experimental data. Moreover, a good agreement is also observed between the estimated results and those obtained from Berreman’s expression and finite element method (FEM) simulations, respectively. Overall, the experimental and numerical results show that for the nematic liquid crystal considered in the present study (4-n-pentyl-4’-cyanobiphenyl (5CB)), the surface azimuthal anchoring energy increases with an increasing grating height or a reducing grating pitch.

scholarly journals Dissipative structures induced by photoisomerization in a dye-doped nematic liquid crystal layer

2018 ◽  
Vol 376 (2135) ◽  
pp. 20170382 ◽  
Author(s):  
I. Andrade-Silva ◽  
U. Bortolozzo ◽  
C. Castillo-Pinto ◽  
M. G. Clerc ◽  
G. González-Cortés ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Dissipative Structures ◽  
Input Power ◽  
Isotropic Phase ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Nematic Liquid Crystal Layer ◽  
Interface Propagation

Order–disorder phase transitions driven by temperature or light in soft matter materials exhibit complex dissipative structures. Here, we investigate the spatio-temporal phenomena induced by light in a dye-doped nematic liquid crystal layer. Experimentally, for planar anchoring of the nematic layer and high enough input power, photoisomerization processes induce a nematic–isotropic phase transition mediated by interface propagation between the two phases. In the case of a twisted nematic layer and for intermediate input power, the light induces a spatially modulated phase, which exhibits stripe patterns. The pattern originates as an instability mediated by interface propagation between the modulated and the homogeneous nematic states. Theoretically, the phase transition, emergence of stripe patterns and front dynamics are described on the basis of a proposed model for the dopant concentration coupled with the nematic order parameter. Numerical simulations show quite a fair agreement with the experimental observations. This article is part of the theme issue ‘Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)’.

Tunable Terahertz Filter Using an Etalon with a Nematic Liquid Crystal Layer and its Response Speed

2012 ◽  
Vol 561 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Takayuki Kumagai ◽  
Ryouta Ito ◽  
Kei Takeya ◽  
Hiroyuki Yoshida ◽  
Hitoshi Kubo ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Response Speed ◽  
Crystal Layer ◽  
Liquid Crystal Layer ◽  
Nematic Liquid Crystal Layer ◽  
Terahertz Filter
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