scholarly journals Position sensitive, continuous wavelength tunable laser based on photopolymerizable cholesteric liquid crystals with an in-plane helix alignment

2009 ◽  
Vol 94 (9) ◽  
pp. 093306 ◽  
Author(s):  
Hiroyuki Yoshida ◽  
Yo Inoue ◽  
Takuya Isomura ◽  
Yuko Matsuhisa ◽  
Akihiko Fujii ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Tunable Laser ◽  
Cholesteric Liquid Crystals ◽  
Wavelength Tunable ◽  
Position Sensitive

scholarly journals Wavelength-tunable and shape-reconfigurable photonic capsule resonators containing cholesteric liquid crystals

2018 ◽  
Vol 4 (6) ◽  
pp. eaat8276 ◽  
Author(s):  
Sang Seok Lee ◽  
Jong Bin Kim ◽  
Yun Ho Kim ◽  
Shin-Hyun Kim
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Wavelength Tunable

scholarly journals Multifunctional Optical Device with a Continuous Tunability over 500 nm Spectral Range Using Polymerized Cholesteric Liquid Crystals

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3720
Author(s):  
Mi-Yun Jeong ◽  
Hyeon-Jong Choi ◽  
Keumcheol Kwak ◽  
Younghun Yu
Keyword(s):  
Liquid Crystals ◽  
Spectral Range ◽  
Near Infrared ◽  
Polarized Light ◽  
Cholesteric Liquid Crystals ◽  
Laser Beam Intensity ◽  
Optical Device ◽  
Circularly Polarized Light ◽  
Wavelength Tunable ◽  
Many Instruments

We report that polymerization makes a robust, practically applicable multifunctional optical device with a continuous wavelength tunable over 500 nm spectral range using UV-polymerizable cholesteric liquid crystals (CLCs). It can be used as a circular polarizer generating an extremely high degree of circularly polarized light with |g| = 1.85~2.00. It can also be used for optical notch filters, bandwidth-variable (from ~28 nm to ~93 nm) bandpass filters, mirrors, and intensity-variable beam splitters. Furthermore, this CLC device shows excellent stability owing to the polymerization of CLC cells. Its performance remains constant for a long time (~2 years) after a high-temperature exposure (170 °C for 1 h) and an extremely high laser beam intensity exposure (~143 W/cm2 of CW 532 nm diode laser and ~2.98 MW/cm2 of Nd: YAG pulse laser operation for two hours, respectively). The optical properties of polymerized CLC were theoretically analyzed by Berreman’s 4 × 4 matrix method. The characteristics of this device were significantly improved by introducing an anti-reflection layer on the device. This wavelength-tunable and multifunctional device could dramatically increase optical research efficiency in various spectroscopic works. It could be applied to many instruments using visible and near-infrared wavelengths.

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.

scholarly journals Pitch tuning induced by optical torque in heliconical cholesteric liquid crystals

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
G. Nava ◽  
F. Ciciulla ◽  
O. S. Iadlovska ◽  
O. D. Lavrentovich ◽  
F. Simoni ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Cholesteric Liquid Crystals ◽  
Optical Torque
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