Light Polarizer Based on Anisotropic Nematic Gel With Electrically Controlled Anisotropy of Scattering

2010

Macromolecules

We report the experimental observation of light induced self-organization of 2D periodic structures at the liquid interface of thick nematic liquid crystal and thin reactive mesogen layers. We believe that the long scale thermal fluctuations initiate interpenetration of those two molecular species, and the geometrical asymmetry and matrix-imposed anisotropy result in very specific symmetry properties of the final blend. The photo-polymerization of the reactive mesogen is further amplifying its spatial redistribution and is fixing (stabilizing) the obtained liquid-crystal/surface-attached polymer network. The application of a strong electric field is definitely adjusting that network in terms of morphology and electro-optical response. The origin of the formation of regular and oriented periodic structures remains unclear.

Section: Discussionsupporting

confidence: 70%

Self-Organization of Liquid-Crystal and Reactive-Mesogen into 2D Surface-Stabilized Structures

Bédard-Arcand

2010

Macromolecules

“…We named such a system surface PSLC (S-PSLC), given that the polymer network (made from the RM) here is "attached" to the surface of the substrate instead of being dispersed in the volume of the LC cell. The use of rubbed polyimide obviously created an easy axis [13,14] and, respectively, a strong polarization dependence of light scattering (note that the anisotropic scattering happens also in bulk PSLC systems [20]). …”

Section: Introductionmentioning

confidence: 99%

Programmable and electrically controllable light scattering from surface-polymer stabilized liquid crystals

Bédard-Arcand

2012

J. Opt. Soc. Am. A

We report the creation and study of a polarization independent light scattering material system based on surface-polymer stabilized liquid crystals. Originally isotropic cell substrates with thin nonpolymerized reactive mesogen layers are used for the alignment of pure nonreactive nematic liquid crystals. The partial interdiffusion of the two materials followed by the application of orienting external electric and magnetic fields and the photo polymerization of the reactive mesogen allow us the control of electro-optic scattering properties of obtained cells.

“…Bassene and T. V. Galstian multiple scattering may also demonstrate strong anisotropic character too (with polarization discrimination factors up to 600), but its electrical tuning still shows a rather monotone variation of scattering without interferential oscillations [5,11,12].…”

mentioning

confidence: 97%

Electrical Modulation of Coherent Scattering in Dual Frequency Liquid Crystal Tissue Models

Bassene

Molecular Crystals and Liquid Crystals

2010

Molecular orientation clusters are created in a cell of non aligned liquid crystal to study the light propagation in electrically controllable anisotropic non uniform media. Coherent scattering phenomenon and predominant role of large orientation clusters in such scattering are demonstrated. Fast relaxation of molecular orientation and modulation of light scattering in those clusters is obtained by using ''dual frequency'' liquid crystal mixtures and frequency modulation of the drive signal. The obtained results show the good potential for the creation of electrically tunable tissue models by using liquid crystalline materials.