Nematic Homogeneous Alignment Regulated by the Polarization Photochromism of Surface Azobenzenes

Abstract
Alignment modulation of a nematic liquid crystal was performed by a polarization-selective photochromic reaction of surface azobenzenes. The alignment was changed from an initial perpendicular state to a homogeneous planar state by exposure to the linearly polarized UV light. The induced homogeneous axis was perpendicular to the electric polarization of the reaction light. Rotation of the homogeneous axis was demonstrated by changing the light polarization, and the corresponding relaxation time was measured by laser pulse experiments.