Tilt Angle Generation for Nematic Liquid Crystal on Blended Homeotropic Polyimide Layer Containing Trifluoromethyl Moieties

2003 ◽  
Vol 42 (Part 1, No. 4A) ◽  
pp. 1713-1714 ◽  
Author(s):  
Jeoung-Yeon Hwang ◽  
Seung Hee Lee ◽  
Seung Kwon Paek ◽  
Dae-Shik Seo
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Polyimide Layer

ON AN ORIENTATION TRANSITION IN NEMATIC LIQUID CRYSTALS INDUCED BY THE THICKNESS OF THE SAMPLE

1993 ◽  
Vol 07 (18) ◽  
pp. 1215-1222
Author(s):  
A. L. ALEXE-IONESCU
Keyword(s):  
Experimental Data ◽  
Phase Transitions ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Critical Thickness ◽  
Large Range ◽  
Square Root ◽  
Chiral Molecules ◽  
Homeotropic Orientation

An orientation transition observed in nematic liquid crystal samples, induced by the thickness, is interpreted in a new way. By supposing that the nematic liquid crystal contains chiral impurities, it is shown that the homeotropic orientation is stable only for thicknesses smaller than a critical one, and is dependent on the concentration of the chiral molecules. At the critical thickness, the transition from the homeotropic orientation to the distorted one is characterized by a tilt angle proportional to the square root of the actual thickness minus the critical one. This trend is typical of second order phase transitions. The agreement between the theory and the experimental data is fairly good over a large range of thickness of the sample.

Effect of the Polymer Tilt Angle for Generation of Pretilt Angle in Nematic Liquid Crystal on Rubbed Polyimide Surfaces

1995 ◽  
Vol 34 (Part 2, No. 4B) ◽  
pp. L503-L506 ◽  
Author(s):  
Dae-Shik Seo ◽  
Kazuo Araya ◽  
Norihiro Yoshida ◽  
Michinori Nishikawa ◽  
YoshikazuYabe ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Pretilt Angle

scholarly journals Characterization of large tilt-angle flexoelectro-optic switching in chiral nematic liquid crystal devices

2018 ◽  
Vol 46 (3) ◽  
pp. 408-414 ◽  
Author(s):  
Xiuze Wang ◽  
Julian A. J. Fells ◽  
Chris Welch ◽  
Maria-Gabriela Tamba ◽  
Georg H. Mehl ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Liquid Crystal Devices ◽  
Chiral Nematic

Tilt angle change of nematic liquid crystal as a function of the number of graphite layers

2012 ◽  
Vol 40 (2) ◽  
pp. 216-220 ◽  
Author(s):  
Jeong Seon Yu ◽  
Ji Eun Yun ◽  
Jong-Hyun Kim
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Angle Change

scholarly journals Optically-driven switching of a planar nematic liquid crystal cell with parallel rubbing

2017 ◽  
Vol 9 (2) ◽  
pp. 39
Author(s):  
Varsenik Nersesyan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Light Propagation ◽  
Domain Walls ◽  
Optical Field ◽  
Liquid Crystal Cell ◽  
Crystal Cell ◽  
Order Of Magnitude

This letter reports on the switching of a planar nematic liquid crystal cell with parallel rubbing of the alignment layers, under the application of a voltage, when there is initially an optical field. The voltage application over the liquid crystal in such a cell leads normally to the formation of multiple domains because there is the two switching directions are equivalent. However, an incident optical field under an angle will locally reorient the director and break the symmetry between the equivalent switching directions. The subsequent application of a voltage pulse amplifies the tilt angle and leads to the formation of a dominant domain, with an order of magnitude larger size than the optical beam profile. Several switching conditions are demonstrated for different incident angles of the beam. It is shown that the final switching direction of the entire cell is determined by the tilt angle of the optical field. The lensing effects due to the modified director distribution in the domain walls is analyzed qualitatively. Full Text: PDF ReferencesI. C. Khoo, Liquid crystals (2nd ed. Hoboken (NJ), Wiley, 2007) CrossRef A. Zolotko, V. Kitaeva, N. Kroo et al. OCBP. JETP Lett. 32, 158?162 (1980). DirectLink J. Beeckman, K. Neyts, X. Hutsebaut X, et al. "Simulations and experiments on self-focusing conditions in nematic liquid-crystal planar cells", Opt Express, 12, 1011? 1018 (2004). CrossRef M. Peccianti, C. Conti, G. Assanto, et al. "Electrically assisted self-confinement and waveguiding in planar nematic liquid crystal cells", Appl. Phys. Lett. 77, 7 ? 9 (2000). CrossRef N. Kravets, A. Piccardi, A. Alberucci et al, "Bistability with Optical Beams Propagating in a Reorientational Medium", Phys. Rev. Lett. 113, 023901 (2014) CrossRef A. Piccardi, N. Kravets, A. Alberucci et al, "Voltage-driven beam bistability in a reorientational uniaxial dielectric", APL Photonics 1, 011302 (2016). CrossRef V. Nersesyan, T. Brans, F. Beunis, R. Drampyan , J. Beeckman, K. Neyts, "Light-controlled reorientation of nematic liquid crystal driven by an electric field", Liquid crystals, 43, 1422-1430 (2016). CrossRef J. Beeckman, K. Neyts, W. Cort, et al. "Non-linear light propagation and bistability in nematic liquid crystals", Proc SPIE 7414, 74140K (2009). CrossRef

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