We study the effects of chirality at the segment scale on the thermodynamics of block copolymer melts using self-consistent field theory. In linear diblock melts where segments of one block prefer a twisted, or cholesteric, texture, we show that melt assembly is critically sensitive to the ratio of random coil size to the preferred pitch of cholesteric twist. For weakly chiral melts (large pitc...

The influence of applied electric fields on the pretransitional optical activity Ii) in the chiral nematic 4-cyano-4-(2-methyl)butylphenyl (CB15) was investigated. A rotating analyzer system was used to measure the optical activity and fields

4-Cyanoresorcinol derived bent-core molecules with a chiral (S)-2-methylbutoxy chain form liquid crystalline phases with TGBA- and TGBC-like structures at the transition from cybotactic nematic via SmA to SmC phases.

A broadband polarization switch consisting of an active twisted nematic liquid crystal cell and two passive uniaxial compensation films is analysed. The conjugate gradient method was used for optimizing the device parameters. Simulation results indicate that the polarization switch exhibits a broad bandwidth and high contrast ratio. The manufacturing tolerances on cell gap, twist angle and comp...

Optical reorientational nonlinearity in twisted nematic liquid crystalline planar waveguide is analyzed theoretically. It is shown that optical nonlinearity for guided modes in analyzed waveguides can be approximated by saturation nonlinearity. Predicted nonlinearity is large enough to observe e¤ects like spatial solitons formation with milliwatts of light power. PACS: 42.65.Wi, 42.70.Df

We present a Monte Carlo simulation of a model of a twisted nematic display on a lattice starting from purely microscopic interactions. We visualize the simulated display calculating optical textures under crossed polarizers corresponding to the Monte Carlo microscopic configurations. We also investigate the orientational order and the molecular organizations in the different regions of the lat...

We analyze the bending response to light or heat of a solid nematic disk with a director twisted from being radial on the upper surface to be azimuthal on the lower. We find a number of curl lobes determined purely by the geometry of the mechanical frustration that arises during the response.

Several new nematic bistable liquid crystal displays based on a new alignment surface have been demonstrated. Nano-textured alignment surfaces enable the generation of arbitrary pretilt angles and arbitrary anchoring energy. Based on such surfaces, three types of bistable devices have been developed. They are bistable bend-splay, bistable twist-twist and bistable bend-twisted displays.

A novel photoaligned twisted nematic liquid crystal display (TN-LCD) cell is fabricated by one-step illumination with oblique nonpolarized UV light of an empty cell with azo-dye layers coated on indium tin oxide (ITO) substrates. If the incident angle is sufficiently large (>75 ), the p-polarization of the light is more pronounced for the bottom azo-dye layer in comparison with that for the upp...

Liquid-crystal active lenses are classical imaging systems in which a liquid-crystal spatial light modulator is placed in a pupil plane. The modulator controls the phase of the optical wave in the pupil and achieves an arbitrary wavefront shape, that is limited only by the available modulation depth and resolution. The possibility of using a twisted-nematic liquid-crystal television in the pupi...