A RADIAL MOLECULAR-ORIENTATION USING A FLOW-INDUCED ALIGNING METHOD IN A NEMATIC LIQUID-CRYSTAL CELL

The radially symmetrical molecular orientation is demonstrated by using a flow-induced aligning method in a nematic liquid crystal (LC) on a PVA-coated substrate without a rubbing treatment. The radial molecular orientation of good quality is obtained as compared with the LC cell using a radial rubbing treatment. The diameter of the area with the radial orientation is above five times larger than that obtained by a memory effect of molecular orientation in an electric field produced by a hole-patterned electrode structure. A radially and homogeneously aligned LC cell is prepared, and a molecular orientation state and polarization converting properties are clarified by observations of transmission images and measurements of transmission properties. The effect of a chiral dopant in the LC cell is also investigated, and it is found that the chiral pitch of LC materials can be determined by a rotation angle of disclination line.