Impact of the Liquid Crystal Director Twisting on Two-Beam Energy Exchange in a Hybrid Photorefractive Inorganic-Liquid Crystal Cell

We studied the energy transfer between light beams on the director grating in a hybrid photorefractive liquid crystal (LC) cell assuming the propagation of light waves in the cell to be in the Mauguin regime. This approach makes it possible to trace the change of the gain coefficient dependence on the director grating spacing with the change of the LC director twist. Conditions for the LC flexoelectric parameters and the director helix pitch necessary for transformation the gain coefficient dependence from the nematic to cholesteric type are obtained. The influence of the director splay and bend deformations on the gain coefficient is also studied.

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Two-beam energy exchange in a hybrid photorefractive-flexoelectric liquid-crystal cell

Physical Review E ◽

10.1103/physreve.81.031705 ◽

2010 ◽

Vol 81 (3) ◽

Cited By ~ 16

Author(s):

V. Yu. Reshetnyak ◽

I. P. Pinkevych ◽

G. Cook ◽

D. R. Evans ◽

T. J. Sluckin

Keyword(s):

Liquid Crystal ◽

Beam Energy ◽

Energy Exchange ◽

Liquid Crystal Cell ◽

Crystal Cell

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Interplay of Thermo-Optic and Reorientational Responses in Nematicon Generation

Materials ◽

10.3390/ma11101837 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1837 ◽

Cited By ~ 2

Author(s):

Urszula Laudyn ◽

Armando Piccardi ◽

Michal Kwasny ◽

Bartlomiej Klus ◽

Miroslaw Karpierz ◽

...

Keyword(s):

Signal Processing ◽

Liquid Crystal ◽

Excellent Agreement ◽

Material Properties ◽

Soft Matter ◽

Simplified Model ◽

Nonlinear Beam ◽

Propagation Of Light ◽

Linear And Nonlinear ◽

Light Beams

Employing several nematic liquid crystal mixtures, we investigate how the thermo-optic response of nonlinear birefringent soft-matter affects the propagation of light beams and the features of self-induced waveguides. We address the formation of optical spatial solitons and the control of their trajectories versus temperature, comparing the measurements with the expectations based on a simplified model, showing an excellent agreement. Moreover, in a guest–host mixture with an absorbing dye dopant, we study the competition between reorientational and thermal nonlinearities, demonstrating that the two processes can be adjusted independently in order to tune the soliton properties, i.e., trajectory and confinement strength. Our results are an important contribution to better comprehend the role played by material properties on linear and nonlinear beam propagation, as well as their exploitation for signal processing and addressing.

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Light-Induced Ring Pattern in a Dye-Doped Nematic Liquid Crystal

Applied Sciences ◽

10.3390/app11115285 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5285

Author(s):

Marcel G. Clerc ◽

Gregorio González-Cortés ◽

Paulina I. Hidalgo ◽

Lucciano A. Letelier ◽

Mauricio J. Morel ◽

...

Keyword(s):

Liquid Crystal ◽

Liquid Crystals ◽

Phase Modulation ◽

Order Parameter ◽

Liquid Crystal Cell ◽

The Self ◽

Self Organization ◽

Experimental Setup ◽

Coherent Beams ◽

Light Beams

The use of dye-doped liquid crystals allows the amplification of the coupling of light and liquid crystals. Light can induce the self-organization of the molecular order. The appearance of ring patterns has been observed, which has been associated with phase modulation. However, the morphology and dynamics of the ring patterns are not consistent with self-modulation. Based on an experimental setup with two parallel coherence beams orthogonal to a liquid crystal cell, one of which induces photo-isomerization and the other causes illumination, the formation of ring patterns is studied. To use these two coherent beams, we synthesize methylred methyl ester as a dye-dopant, which is photosensitive only to one of the light beams, and a commercial E7 liquid crystal as a matrix. Based on a mathematical model that accounts for the coupling between the concentration of the cis-state and the order parameter, we elucidate the emergence of the rings as forming patterns in an inhomogeneous medium. The bifurcation diagram is analytically characterized. The emergence, propagation of the rings, and the establishment of the ring patterns are in fair agreement with the experimental observations.

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