Ultrafast switching of randomly-aligned nematic liquid crystals.

We propose an ultrafast nematic liquid crystal (LC) device without alignment layers, where both the dark and bright states can be realized by applying an electric field. A vertical electric field is applied to vertically align the LCs for the dark state, whereas an in-plane electric field is applied to homogeneously align the LCs for the bright state. We achieved a total response time of less than 3 ms in the proposed device.

Vertical alignment of liquid crystals with negative dielectric anisotropy on an inorganic thin film with a hydrophilic surface.

The vertical alignment of liquid crystals having negative dielectric anisotropy on an amorphous silicon oxide (a-SiO(x)) thin film is the consequence of the anisotropic interaction between liquid crystals and a-SiO(x) thin films. To investigate the mechanism of the vertical alignment, we changed the physicochemical characteristics of alignment layers by controlling the composition, since the anisotropic interaction depends on the nature of both liquid crystals and an alignment layer. The variation of composition gives rise to a change in the polarizability, which is a simple measure of induced-dipole strength at the surface of the alignment layer.