Enhancement of stability in optical switching of photosensitive liquid crystal by means of reflection mode analysis

1999 ◽  
Vol 9 (9) ◽  
pp. 2211-2213 ◽  
Author(s):  
Atsushi Shishido ◽  
Akihiko Kanazawa ◽  
Takeshi Shiono ◽  
Tomiki Ikeda ◽  
Naoto Tamai
Keyword(s):  
Liquid Crystal ◽  
Optical Switching ◽  
Mode Analysis ◽  
Reflection Mode

Liquid Crystal Photonics: Optical Switching and Image Storage by Means of Azobenzene Liquid-Crystal Films

1996 ◽  
Vol 425 ◽  
Author(s):  
A. Shishido ◽  
O. Tsutsumi ◽  
T. Ikeda
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Optical Switching ◽  
Transmission Mode ◽  
Mode Analysis ◽  
Reflection Mode ◽  
Image Storage ◽  
Liquid Crystal Films ◽  
Crystal Films ◽  
One Year

AbstractOptical switching and image storage were explored by means of azobenzene liquid crystals (LCs). Azobenzene derivatives with monomeric and polymeric forms were prepared, which show nematic LC phase in the trans form while no LC phase in the cis form. On pulse irradiation at 355 nm, which causes trans-cis isomerization of the azobenzene moiety, these azobenzene LC films underwent nematic (N) to isotropic (1) phase transition in 100 ˜ 200 μs as probed by change in transmittance of a He-Ne laser through crossed polarizers (transmission-mode analysis) or change in reflectivity at the interface between the sample and glass substrate (reflection-mode analysis). In the reflection-mode analysis, the decay was faster than that observed in the transmission-mode analysis. The N phase recovered through the cis-trans thermal backisomerization process in the transmission-mode analysis, while it was restored through diffusion of the cis form, followed by reorientation of the trans form which replaced the cis form in the interface region, in the reflection-mode analysis. The photochemical N-I phase transition was also induced in 200 μs below Tg of the polymer azobenzene LC. Image could be stored into the polymer azobenzene LC film on photoirradiation to bring about the N-I phase transition and the stored image remained unchanged even after one year when it was kept below Tg of the polymer.

Rapid Optical Switching by Means of Photoinduced Change in Refractive Index of Azobenzene Liquid Crystals Detected by Reflection-Mode Analysis

1997 ◽  
Vol 119 (33) ◽  
pp. 7791-7796 ◽  
Author(s):  
Atsushi Shishido ◽  
Osamu Tsutsumi ◽  
Akihiko Kanazawa ◽  
Takeshi Shiono ◽  
Tomiki Ikeda ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Optical Switching ◽  
Mode Analysis ◽  
Photoinduced Change ◽  
Reflection Mode

Reflection-Mode Optical Switching of Polymer Azobenzene Liquid Crystal

1998 ◽  
Vol 318 (1) ◽  
pp. 59-70
Author(s):  
Atsushi Shishido ◽  
Osamu Tsutsumi ◽  
Akihiko Kanazawa ◽  
Takeshi Shiono ◽  
Tomiki Ikeda
Keyword(s):  
Liquid Crystal ◽  
Optical Switching ◽  
Reflection Mode

scholarly journals ELECTRO-OPTICAL SWITCHING OF THE MAIN OPTICAL AXIS OF A FERROELECTRIC LIQUID CRYSTAL SPIRAL NANOSTRUCTUREIN A PLANAR-ORIENTED DISPLAY CELL

Doklady BGUIR ◽  
2019 ◽  
pp. 21-27
Author(s):  
E. P. Pozhidaev ◽  
T. P. Tkachenko ◽  
A. V. Kuznetsov ◽  
I. N. Kompanets
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Optical Switching ◽  
Optical Axis ◽  
Modulation Frequency ◽  
Light Transmittance ◽  
Weak Electric Field ◽  
Ferroelectric Liquid Crystal ◽  
Light Modulation ◽  
Small Pitch

In a known display cell with the nematic liquid crystal (NLC) and interdigital electrodes on one of the glass substrates, the “In-Plane Switching” (IPS) mode is implemented, in which the NLC main optical axis reorients in a plane parallel to substrates, providing the most correct color reproduction at different angles view, up to 178 ° horizontally and vertically. Unfortunately, the creation of interdigital metal electrodes complicates and increases the technological process cost and causes a decrease in image contrast. At the same time, experimental results and calculations based on classical electro-optics of crystals indicate that electrooptical switching in the IPS mode is a natural and intrinsic feature of a conventional (with continuous electrodes) display cell with a planar-oriented layer of the ferroelectric liquid crystal (FLC), in which the effect of the deformed (by the electric field) helix FLC nanostructure is realized (DHF effect). In such a cell, the reorientation of the main optical axis under the influence of a weak electric field also occurs in the substrate plane if the FLC has a small pitch (about 100 nm or less) and a large tilt angle of molecules in the layer (about 38 ° or more). The dependences of the FLC cell light transmittance measured in this work, confirmed the achievement of the IPS electro-optical mode in the DHF FLC cell; moreover, the light modulation frequency was 1 kHz. Thus, while maintaining all the advantages of the IPS mode known in NLC, its implementation in FLC allows additionally obtaining technological advantages and multiple increase in modulation frequency.

ChemInform Abstract: Distinct Photochemical Phase Transition Behavior of Azobenzene Liquid Crystals Evaluated by Reflection-Mode Analysis.

ChemInform ◽  
2010 ◽  
Vol 28 (28) ◽  
pp. no-no
Author(s):  
A. SHISHIDO ◽  
O. TSUTSUMI ◽  
A. KANAZAWA ◽  
T. SHIONO ◽  
T. IKEDA ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Mode Analysis ◽  
Phase Transition Behavior ◽  
Reflection Mode ◽  
Transition Behavior

Electrical Characterization of E7 Liquid Crystal Molecules under the Impact of an External Electric Field (THz): A Theoretical approach

2020 ◽  
Vol 15 (2) ◽  
pp. 95-101
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Order Parameter ◽  
Optical Switching ◽  
Rapid Change ◽  
Electrical Characterization ◽  
Optical Switching Devices ◽  
The Impact ◽  
Orientation Of Molecules

In this work, different parameters of E7 liquid crystal (LC) have been calculated under the influence of an electric field in THz frequency. The E7 LC parameters have positive as well as negative values of order parameter and birefringence under the influence for an electric field. The director angle of E7 LC shows fast fluctuations above the angle θ=45° and due to rapid change in the orientation of molecules, fast electro-optical switching devices based on E7 LC can be designed. The refractive index of the E7 LC maintains stability in THz frequency.

scholarly journals In-plane Switching Deformed Helix Ferroelectric Liquid Crystal Display Cells

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 543 ◽  
Author(s):  
Evgeny P. Pozhidaev ◽  
Timofey P. Tkachenko ◽  
Artemy V. Kuznetsov ◽  
Igor N. Kompanets
Keyword(s):  
Liquid Crystal ◽  
Tilt Angle ◽  
Optical Switching ◽  
Liquid Crystal Display ◽  
Ferroelectric Liquid Crystal ◽  
Natural Feature ◽  
Helix Pitch ◽  
Sub Wavelength

In-plane electro-optical switching (IPS) is a natural feature of a conventional planar-aligned display cell based on the deformed helix ferroelectric liquid crystal effect (DHFLC-effect) with a sub-wavelength helix pitch, if the tilt angle is close to 40 degrees.

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