摘要:

The equation for spectral noise power density of surface liquid crystal droplets (SLCD) films for coherent transmitted light has been obtained. Monodisperse hemi-sphere-shaped droplets of a bistable ferroelectric liquid crystal (LC) with homogeneous planar orientation of directors are considered. Assuming nonoverlapping discs, we analyze the influence of spatial correlation in the arrangement of droplets on the spectral noise and the signal-noise ratio.

ISSN:1058-725X    

DOI:10.1080/10587250008023195

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

We present electro-optic switching from a planar waveguide with a ferroelectric liquid crystal overlayer and discuss the operating principle and the parameters significant for the operation of the device. We have found electro-optic response times of about 20 μs at best as well as a high (5.7%) transmittance in the ON-state of the device. The contrast ratio was 4:1 ON to OFF state.

ISSN:1058-725X    

DOI:10.1080/10587250008023196

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The differential cross-sections of the light scattering by the director inhomogeneity near small spherical and cylindrical particles in nematic liquid crystals are calculated in the Rayleigh-Gans approximation. We use the Percus-Yevick approximation to account for interference effects. The influence of the boundary conditions at the particle surface as well as of external electric field on the angular dependence and magnitude of the light scattering cross-section is studied.

ISSN:1058-725X    

DOI:10.1080/10587250008023197

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Reflection gratings are formed holographically in polymer dispersed material. The effect of polymer functionality on the reflective display performance characteristics of these materials is investigated. Commercial urethane resins of functionality 2, 3, and 6 are used as base materials to create integer and half-integer effective functionalities from 2 to 6. Our results reveal an optimum reflectance at an effective functionality of 4.5.

ISSN:1058-725X    

DOI:10.1080/10587250008023198

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Oriented photopolymer films were obtained by using electric field alignment of the cinnamoyl side groups near the glass transition temperature of poly(vinyl)cinnamate (PVCN) followed by photo-polymerization using unpolarized UV light. In this way the induced anisotropy could be fixed and was subsequently shown to lead to a well aligned liquid crystal texture. The combination of electric field and UV light offers a solution to the pretilt angle problem for photo-aligned substrates.

ISSN:1058-725X    

DOI:10.1080/10587250008023199

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Side chain type polyethers were synthesized by ring opening polymerization of glycidyl ether with p-alkoxyphenyl moiety. A liquid crystalline phase was found at the alkoxy chain length of below 12. A smectic phase was induced for the mixture of the non-mesomorphic polyethers with alkali metal salt, and the mesomorphic temperature range for the mixed system of the polyethers became wider with increasing amounts of alkali metal salt. These mixtures had ionic conductivity. The ionic conductivity of the mesomorphic polyethers with alkali metal salt was larger than that of the non-mesomorphic polyethers with same alkali metal concentration in the whole measured temperature range. Activation energy of the smectic phase region was larger than that of the isotropic phase region. The ionic conductivity of the liquid crystalline polyether with LiClO4was 5.3 8×10−6Scm−1and that of the non-mesomorphic polyether was 4.57×10−7Scm−1at 100°C.

ISSN:1058-725X    

DOI:10.1080/10587250008023200

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A new principle of information storage based on a realization of the reversible transition <<selective reflection-absorbance>> in photochromic liquid crystalline (LC) copolymers was suggested. For this purpose a new family of triple copolymers were synthesized by copolymerization of acrylic monomers, containing nematogenic (phenylbenzoate), chiral (cholesterol), and photochromic (spiropyran) fragments. Phase behaviour and optical properties of copolymers were studied. Isomerization of spiropyran groups and formation of merocyanine form under UV-irradiation (337 nm) of the polymer films was observed. It should be noted that the maximum of the absorbance of polymer films coincides with maximum of selective light reflection. As a result the disappearance of the selective light reflection in the irradiated regions of the films occurs. Scheme of the optical data recording and reading of information recorded on planarly oriented films of such copolymers was proposed.

ISSN:1058-725X    

DOI:10.1080/10587250008023201

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Two new classes of chiral side-chain polymers comprising a variously spaced biphenyl unit as both a mesogenic core and a fluorescent chromophore were investigated. The chiral group was either a 2,3- or a 2,2-disubstituted oxirane ring. The structures of the smectic phases (A, B, or E) were investigated by X-ray diffraction. Excimer fluorescence emission was detected at room temperature in the smectic phase.

ISSN:1058-725X    

DOI:10.1080/10587250008023202

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:1058-725X    

DOI:10.1080/10587250008023154

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor