The spatial chaotization of the optical field scattered by liquid crystals

2013 ◽  
Author(s):  
M. S. Gavrylyak ◽  
P. P. Maksimyak ◽  
O. S. Kshevetsky
Keyword(s):  
Liquid Crystals ◽  
Optical Field

CHARACTERIZATION OF DIFFERENT REGIMES IN NONLINEAR LIQUID CRYSTAL MODELS

2012 ◽  
Vol 21 (03) ◽  
pp. 1250042 ◽  
Author(s):  
I. ORQUÍN-SERRANO ◽  
F. R. VILLATORO ◽  
A. FERRANDO ◽  
P. FERNÁNDEZ DE CÓRDOBA ◽  
H. MICHINEL
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Critical Role ◽  
Optical Power ◽  
Initial Position ◽  
Optical Field ◽  
Planar Cells ◽  
Nonlocal Nonlinear

The range of validity of two models for nonlocal nonlinear optics in Nematic Liquid Crystals (NLC) is studied. Particularly the influence of the optical power and the initial position of the beam over its trajectory is studied when launching the beam with an offset in a planar cell. The main difference between both models is the dependence of the orientational angle with the optical field, either linear or nonlinear. The results demonstrate the critical role of the nonlinearity in the propagation of nematicons in NLC planar cells.

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

Optical nonlinearity and bistability in liquid crystals

1984 ◽  
Vol 313 (1525) ◽  
pp. 327-332 ◽  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Laser Beam ◽  
Laser Heating ◽  
Optical Bistability ◽  
Optical Nonlinearity ◽  
Optical Field ◽  
Refractive Indices ◽  
Phase Retardation ◽  
Molecular Reorientation

Molecular reorientation and laser heating induced by an optical field can yield significant changes in the refractive indices in a nematic liquid crystal. A c.w. laser beam is intense enough to induce a phase retardation much larger than 2pi in a nematic film less than 100 pm thick. Optical bistability in such a film sandwiched between mirrors can be readily observed. Coupling between the two mechanisms for induced refractive indices can lead to interesting results in the bistable operation.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

High-performance light transmission based on graphene plasmonic waveguides

2020 ◽  
Vol 8 (20) ◽  
pp. 6832-6838 ◽  
Author(s):  
Da Teng ◽  
Kai Wang ◽  
Qiongsha Huan ◽  
Weiguang Chen ◽  
Zhe Li
Keyword(s):  
High Performance ◽  
Light Transmission ◽  
Optical Field ◽  
Plasmonic Waveguides ◽  
Rib Waveguide

Tunable ultra-deep subwavelength optical field confinement is reported by using a graphene-coated nanowire-loaded silicon nano-rib waveguide.

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