About defect mode peculiarities in cholesteric liquid crystals with anisotropic defect layer inside

Optik ◽  
2018 ◽  
Vol 154 ◽  
pp. 656-661 ◽  
Author(s):  
A.H. Gevorgyan
Keyword(s):  
Liquid Crystals ◽  
Defect Mode ◽  
Defect Layer ◽  
Cholesteric Liquid Crystals

scholarly journals CHOLESTERIC LIQUID CRYSTALS WITH TUNABLE DEFECT INSIDE

2011 ◽  
Vol 25 (18) ◽  
pp. 1511-1520 ◽  
Author(s):  
A. H. GEVORGYAN ◽  
K. B. OGANESYAN ◽  
E. M. HARUTYUNYAN ◽  
S. H. HARUTYUNYAN ◽  
E. A. SANTROSYAN
Keyword(s):  
Liquid Crystals ◽  
Layer Thickness ◽  
Defect Mode ◽  
Defect Layer ◽  
Refraction Coefficient ◽  
Cholesteric Liquid Crystals ◽  
Defect Modes ◽  
Defect Location ◽  
Layer Position

Peculiarities of the defect modes of cholesteric liquid crystals (CLCs) with an isotropic/anisotropic defect inside are investigated. The influence of the defect layer thickness and its anisotropy of refraction, the influence of the system thickness and of the defect layer position in the system, as well as the influence of the dielectric borders on the defect modes are investigated. It is shown that it is possible to change reflection at the defect modes in wide intervals and change the defect mode wavelength, by tuning the defect location and its thickness. Such a system possesses transmission asymmetry. Also, the CLC system thickness and the refraction coefficient of the medium bordering the CLC layer on its both sides have essential influence on the reflection at the defect mode and on the reflection frequency.

scholarly journals Polarization characteristics of phase retardation defect mode lasing in polymeric cholesteric liquid crystals

2004 ◽  
Vol 5 (4) ◽  
pp. 437-441 ◽  
Author(s):  
Myoung Hoon Song ◽  
Ki-Chul Shin ◽  
Byoungchoo Park ◽  
Yoichi Takanishi ◽  
Ken Ishikawa ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Defect Mode ◽  
Cholesteric Liquid Crystals ◽  
Phase Retardation ◽  
Polarization Characteristics

scholarly journals Tunable single photonic defect-mode in cholesteric liquid crystals with laser-induced local modifications of helix

2006 ◽  
Vol 89 (23) ◽  
pp. 231913 ◽  
Author(s):  
Hiroyuki Yoshida ◽  
Chee Heng Lee ◽  
Akihiko Fujii ◽  
Masanori Ozaki
Keyword(s):  
Liquid Crystals ◽  
Defect Mode ◽  
Cholesteric Liquid Crystals

Effect of Phase Retardation on Defect-Mode Lasing in Polymeric Cholesteric Liquid Crystals

2004 ◽  
Vol 16 (910) ◽  
pp. 779-783 ◽  
Author(s):  
M. H. Song ◽  
B. Park ◽  
K.-C. Shin ◽  
T. Ohta ◽  
Y. Tsunoda ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Defect Mode ◽  
Cholesteric Liquid Crystals ◽  
Phase Retardation

scholarly journals Synthesis and Characterization of Novel Bio-Chiral Dopants Obtained from Bio-Betulin Produced by a Fermentation Process

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 785
Author(s):  
Veridiana G. Guimarães ◽  
Anastasiia Svanidze ◽  
Tianyi Guo ◽  
Pawan Nepal ◽  
Robert J. Twieg ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Natural Product ◽  
Fermentation Process ◽  
Synthesis And Characterization ◽  
Cholesteric Liquid Crystals ◽  
And Performance ◽  
Chiral Dopants

Cholesteric liquid crystals are frequently produced by the addition of chiral dopants to achiral nematic hosts. We report here the synthesis and performance of chiral dopants obtained from bio-betulin produced by a fermentation process. An important aspect of this work is to point out that the fermentation process used to obtain the starting materials is much easier and cheaper when carried out in large volumes than isolating it from the natural product. The performance of the dopants obtained from bio-betulin is indistinguishable from those obtained from commercially available synthetic betulin.

scholarly journals Augmented Lagrangian preconditioners for the Oseen–Frank model of nematic and cholesteric liquid crystals

2021 ◽  
Author(s):  
Jingmin Xia ◽  
Patrick E. Farrell ◽  
Florian Wechsung
Keyword(s):  
Liquid Crystals ◽  
Augmented Lagrangian ◽  
Augmented Lagrangian Method ◽  
Mass Matrix ◽  
Unit Length ◽  
Mesh Size ◽  
Schur Complement ◽  
Cholesteric Liquid Crystals ◽  
Multigrid Algorithm ◽  
The Cost

AbstractWe propose a robust and efficient augmented Lagrangian-type preconditioner for solving linearizations of the Oseen–Frank model arising in nematic and cholesteric liquid crystals. By applying the augmented Lagrangian method, the Schur complement of the director block can be better approximated by the weighted mass matrix of the Lagrange multiplier, at the cost of making the augmented director block harder to solve. In order to solve the augmented director block, we develop a robust multigrid algorithm which includes an additive Schwarz relaxation that captures a pointwise version of the kernel of the semi-definite term. Furthermore, we prove that the augmented Lagrangian term improves the discrete enforcement of the unit-length constraint. Numerical experiments verify the efficiency of the algorithm and its robustness with respect to problem-related parameters (Frank constants and cholesteric pitch) and the mesh size.

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