Helical polydiacetylene prepared in the liquid crystal phase using circular polarized ultraviolet light.

Berry Phase of Light under Bragg Reflection by Chiral Liquid-Crystal Media.

A Berry phase is revealed for circularly polarized light when it is Bragg reflected by a chiral liquid-crystal medium of the same handedness. By using a chiral nematic layer we demonstrate that if the input plane of the layer is rotated with respect to a fixed reference frame, a geometric phase effect occurs for the circularly polarized light reflected by the periodic helical structure of the m...

Mechanism of Unidirectional Liquid-Crystal Alignment on Polyimides with Linearly Polarized Ultraviolet Light Exposure

A Small Printed Quadrifilar Helical Antenna for BGAN/GPS Applications

This paper presents an element of a 2×2-element array antenna for Inmarsat BGAN/GPS applications. The element is an axial mode printed quadrifilar helical antenna that has been integrated with a compact feed network to provide sequential phase rotation for circular polarization (CP) radiation. The novel integrated lumped-element feed network is designed to provide a balanced RF power to the fou...

Model of liquid crystal alignment by exposure to linearly polarized ultraviolet light.

A simple theoretical model of liquid crystal ͑LC͒ alignment by exposure to linearly polarized ultraviolet ͑UV͒ light is proposed. The model predicts a universal relationship describing the change of the LC anchoring direction with exposure times, and the changes of polarization direction for the case of a double linearly polarized UV exposure process. This relationship is quantitatively confirmed b...

Photoalignment of liquid crystals by liquid crystals

We observed light-induced alignment of the nematic liquid crystal, 4, 4(')-n-pentylcyanobiphenyl (5CB), on a fused quartz. Irradiation of the adsorbed layer with polarized ultraviolet light produced homogeneous alignment in a 5CB-filled liquid crystal cell with the easy orientation axis perpendicular to the polarization direction. The measured anchoring energy increases with illumination up to ...