scholarly journals Efficiency of diffraction gratings based on liquid crystals

2021 ◽  
Vol 9 (2) ◽  
pp. 144-152
Keyword(s):  
Experimental Data ◽  
Liquid Crystal ◽  
Geometric Phase ◽  
Liquid Crystal Cell ◽  
Visible Range ◽  
Radiation Wavelength ◽  
Voltage Amplitude ◽  
Phase Grating ◽  
Dichroic Dye ◽  
532 Nm

Wehave recorded geometric-phase diffraction gratingusing the method of holography on a thin layer of dichroic dye. A transmission liquid crystal cell hasbeen assembled inorder to obtain electrically-controlled diffraction in visible range. Also, using software for electrooptical effects modeling wehavecalculated the diffraction efficiency (DE) of the LC-based phase grating as a function of the voltage amplitude at the electrodes,es-timatedtheDEvariation as a function of LCcell thickness, LC materialbirefringenceand the radiation wavelength. The experimental data qualitatively matched with calcu-lation results. 1-st order DE of16% (at 532 nm) has been obtainedforsingle-sided phase grating LC. Furthermore, we have observed the decrease ofDEwith the increase of radiation wavelength.

Studies on Optical Performances of Dichroic Dye‐doped Nematic Liquid Crystal Cell with a Direct Lamination Reflective Polarizer

2020 ◽  
Vol 51 (S1) ◽  
pp. 172-175
Author(s):  
Xiaojuan Wu ◽  
Zhiqiang Zhao ◽  
Jiaxing Wang ◽  
Hongliang Yuan ◽  
Jian Wang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Liquid Crystal Cell ◽  
Crystal Cell ◽  
Dichroic Dye

scholarly journals Polymer Dispersed Cholesteric Liquid Crystals With a Toroidal Director Configuration under an Electric Field

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 732
Author(s):  
Anna P. Gardymova ◽  
Mikhail N. Krakhalev ◽  
Victor Ya. Zyryanov ◽  
Alexandra A. Gruzdenko ◽  
Andrey A. Alekseev ◽  
...  
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Electric Field ◽  
Point Defects ◽  
Structural Response ◽  
Optical Filters ◽  
Response Curves ◽  
Polymer Dispersed Liquid Crystal ◽  
Dichroic Dye ◽  
Polymer Dispersed

The electro-optical properties of polymer dispersed liquid crystal (PDLC) films are highly dependent on the features of the contained liquid crystal (LC) droplets. Cholesteric LC droplets with homeotropic boundaries can form several topologically different orientational structures, including ones with single and more point defects, layer-like, and axisymmetric twisted toroidal structures. These structures are very sensitive to an applied electric field. In this work, we have demonstrated experimentally and by computer simulations that twisted toroidal droplets reveal strong structural response to the electric field. In turn, this leads to vivid changes in the optical texture in crossed polarizers. The response of droplets of different sizes were found to be equivalent in terms of dimensionless parameters. In addition, the explanation of this phenomenon showed a comparison of theoretical and experimental structural response curves aids to determine the shape of the droplet. Finally, we demonstrated that the addition of a dichroic dye allows such films to be used as optical filters with adjustable color even without polarizers.

Dichroic Azo Dyes for Guest-Host Liquid-Crystal Cell

1982 ◽  
Vol 21 (Part 1, No. 1) ◽  
pp. 191-192 ◽  
Author(s):  
Hidehiro Seki ◽  
Chiyoko Shishido ◽  
Shigeo Yasui ◽  
Tatsuo Uchida
Keyword(s):  
Liquid Crystal ◽  
Azo Dyes ◽  
Liquid Crystal Cell ◽  
Crystal Cell

Liquid crystal cell for space-borne laser rangefinder to space mission applications

2012 ◽  
Vol 20 (4) ◽  
Author(s):  
E. Nowinowski-Kruszelnicki ◽  
L. Jaroszewicz ◽  
Z. Raszewski ◽  
L. Soms ◽  
W. Piecek ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Polarization Plane ◽  
Space Mission ◽  
Liquid Crystal Cell ◽  
Laser Rangefinder ◽  
Aperture Diameter ◽  
Crystal Cell ◽  
University Of Technology ◽  
Twisted Nematic ◽  
Space Requirements

AbstractLiquid crystal cell (LCC) for space-borne laser rangefinder to space mission applications was developed, manufactured and tested under cooperation between Military University of Technology (MUT) in Poland and Vavilov State Optical Institute (Vavilov SOI) in Russia. LCC operates in twisted nematic mode, commutating the polarization plane of a laser beam working at 1.064 μm and the energy density not smaller than 0,15 J/cm2 at the pulse duration about 8 ns. The transmission of LCC is not smaller than 95% at the aperture diameter not less than 15 mm. Switching on and switching off times in a 2.5-μm thick LCC driven by voltage of 10 V are not larger than 0.7 ms and 7 ms, respectively, in the operating temperature range from 20°C to 40°C. The LCCs developed in MUT were positively tested under space requirements in Vavilov SOI.

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