scholarly journals Chiral Liquid Crystals: Tilted Chiral Liquid Crystal Gratings for Efficient Large‐Angle Diffraction (Advanced Optical Materials 22/2019)

2019 ◽  
Vol 7 (22) ◽  
pp. 1970086
Author(s):  
Inge Nys ◽  
Migle Stebryte ◽  
Yera Ye. Ussembayev ◽  
Jeroen Beeckman ◽  
Kristiaan Neyts
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Optical Materials ◽  
Large Angle ◽  
Chiral Liquid Crystal ◽  
Chiral Liquid Crystals

Antiferroelectric Liquid Crystals from Achiral Molecules And A Liquid Conglomerate

1999 ◽  
Vol 559 ◽  
Author(s):  
David M. Walba ◽  
Eva Körblova ◽  
Renfan Shao ◽  
Joseph E. Maclennan ◽  
Darren R. Link ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Crystalline Structures ◽  
Chiral Liquid Crystal ◽  
Antiferroelectric Liquid Crystals ◽  
Liquid Crystal Structure

ABSTRACTUntil recently, it was an empirical fact that creation of a chiral liquid crystal phase required enantiomerically enriched molecules. In addition, to date known ferroelectric and antiferroelectric smectics have also been composed of enantiomerically enriched molecules. Herein are described the first examples of the formation of chiral and antiferroelectric supermolecular liquid crystalline structures from achiral molecules. In one case (apparently metastable) the liquid crystal structure is macroscopically chiral, with samples composed of heterochiral macroscopic domains: a liquid conglomerate.

Structural studies on different types of ferroelectric liquid crystalline substances

2011 ◽  
Vol 35 (1) ◽  
pp. 3-13 ◽  
Author(s):  
D. Obadović ◽  
M. Stojanović ◽  
A. Bubnov ◽  
N. Éber ◽  
M. Cvetinov ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Molecular Conformation ◽  
Large Angle ◽  
Structural Studies ◽  
Layer Spacing ◽  
Different Types ◽  
Intermolecular Distances ◽  
Chiral Liquid Crystals

Structural studies on different types of ferroelectric liquid crystalline substances Structural studies of ferroelectric liquid crystalline substances of different molecular structure have been reviewed. The discussion of the results deals mainly with the structure of chiral liquid crystals forming the smectic mesophase with ferroelectric order, as the research on ferroelectric liquid crystals, due to their high potential for application in electro-optics and photonics, has recently become one of the most attractive fields. Based on data of polarizing optical microscopy and X-ray diffraction obtained for unoriented samples we have identified the type of the mesophases, the temperature of the phase transitions and outlined the phase diagrams. An analysis of the relation between the molecular conformation and different types of phase transitions has been performed. The layer spacing and the average intermolecular distances have been determined for all studied phases from the positions of the small and the large angle diffraction peaks, respectively.

scholarly journals Chiral Compounds: Photoinvertible Chiral Liquid Crystal that Affords Helicity‐Controlled Aromatic Conjugated Polymers (Advanced Optical Materials 20/2020)

2020 ◽  
Vol 8 (20) ◽  
pp. 2070080
Author(s):  
Satoru Yoshida ◽  
Santa Morikawa ◽  
Kenta Ueda ◽  
Masatomo Hidaka ◽  
Kosuke Kaneko ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Conjugated Polymers ◽  
Optical Materials ◽  
Chiral Compounds ◽  
Chiral Liquid Crystal

scholarly journals Large Angle Forward Diffraction by Chiral Liquid Crystal Gratings with Inclined Helical Axis

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 807 ◽  
Author(s):  
Migle Stebryte ◽  
Inge Nys ◽  
Yera Ye. Ussembayev ◽  
Jeroen Beeckman ◽  
Kristiaan Neyts
Keyword(s):  
Liquid Crystal ◽  
Total Internal Reflection ◽  
Large Angle ◽  
Forward Direction ◽  
Visible Range ◽  
Helical Axis ◽  
Chiral Liquid Crystal ◽  
Photo Alignment ◽  
Tilted Plane ◽  
Full Reflection

A layer of chiral liquid crystal (CLC) with a photonic bandgap in the visible range has excellent reflective properties. Recently, two director configurations have been proposed in the literature for CLC between two substrates with periodic photo-alignment: one with the director parallel to the substrates and one with the director in the bulk parallel to the tilted plane. The transmission experiments under large angles of incidence (AOI) presented in this work prove that, in the bulk, the director does not remain parallel with the substrates. Because of the inclined helical axis, the full reflection band can be observed at a smaller AOI than in planar CLC. For sufficiently large AOI, the reflection of diffracted light is prohibited by total internal reflection and efficient diffraction occurs in the forward direction.

scholarly journals Tilted Chiral Liquid Crystal Gratings for Efficient Large‐Angle Diffraction

2019 ◽  
Vol 7 (22) ◽  
pp. 1901364 ◽  
Author(s):  
Inge Nys ◽  
Migle Stebryte ◽  
Yera Ye. Ussembayev ◽  
Jeroen Beeckman ◽  
Kristiaan Neyts
Keyword(s):  
Liquid Crystal ◽  
Large Angle ◽  
Chiral Liquid Crystal

General properties of lasing effect in chiral liquid crystals

2006 ◽  
Vol 14 (4) ◽  
Author(s):  
S. Palto ◽  
N. Shtykov ◽  
B. Umansky ◽  
M. Barnik ◽  
L. Blinov
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Numerical Simulations ◽  
Light Emission ◽  
Experimental Studies ◽  
General Properties ◽  
Chiral Liquid Crystals ◽  
Lasing Condition

AbstractNumerical simulations and experimental studies of the lasing effect in chiral liquid crystals are presented. It is shown that ring-like light emission, which is often observed experimentally, is a true lasing effect. Lasing condition and different modes in thin liquid crystal layers are discussed.

Attractive mode force microscopy of chiral liquid crystal surfaces

1992 ◽  
Vol 50 (1) ◽  
pp. 268-269
Author(s):  
B.D. Terris ◽  
R. J. Twieg ◽  
C. Nguyen ◽  
G. Sigaud ◽  
H. T. Nguyen
Keyword(s):  
Liquid Crystal ◽  
Crystal Surfaces ◽  
Free Surfaces ◽  
Control Range ◽  
Force Microscopy ◽  
Liquid Crystal Films ◽  
Chiral Liquid Crystal ◽  
Crystal Films ◽  
Electrostatic Charging ◽  
And Shifts

We have used a force microscope in the attractive, or noncontact, mode to image a variety of surfaces. In this mode, the microscope tip is oscillated near its resonant frequency and shifts in this frequency due to changes in the surface-tip force gradient are detected. We have used this technique in a variety of applications to polymers, including electrostatic charging, phase separation of ionomer surfaces, and crazing of glassy films.Most recently, we have applied the force microscope to imaging the free surfaces of chiral liquid crystal films. The compounds used (Table 1) have been chosen for their polymorphic variety of fluid mesophases, all of which exist within the temperature control range of our force microscope.

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