Defect in the circular-circularly rubbed liquid crystal cell with off-center alignment

摘要

In this letter, we investigate the behavior of the defects in a circular-circularly rubbed liquid crystal cell with an off-center alignment. We show that the line defect forms a circle that passes through the rubbing centers of the two surfaces. The size and the position of the defect circle depend on the cell gap and the pitch of the materials. We propose a simple model, based on an analysis of the free energy, to explain this interesting phenomenon. This technique of defect making is useful to confine the defect to a particular position by controlling the cell parameters and the material properties. It can also be applied to the pitch measurement, the generation of the space-variant polarized light, and the study of the dynamic properties of the defect.