DISCONTINUOUS RADIAL TO AXIAL TRANSFORMATION OF DIRECTOR CONFIGURATION IN A CYLINDRICAL NEMATIC CAVITY

Abstract

The optical patterns of a nematic liquid crystal confined to a closed cylindrical cavity are observed through crossed polarizers. This optical pattern exhibits an annular phenomenon when the radius of the cylinder is varied. The minor dependence of the width of the bright annulus on the radius of the cavity is presented. The formation of the disclination ring is numerically studied and found to be the physical mechanism of the annular phenomenon. The characteristic length defined as the distance from the ring defect to the laterally cylindrical boundary is nearly invariant and is characterized to be the width of the bright annulus.