8. Textures of Liquid Crystals
Smectic A is a layered liquid crystal with the layer thickness of the order of one or two molecules size. The texture of the focal conic domains (FCDs) structure, most typical for SmA, can be observed if SmA is filled between substrates with planar orientation of the director (Fig.37).
The FCDs texture is created by layers folded around conjugated ellipse and hyperbola.
Toric focal conic domains (TFCDs) are another type of cofocal domains where the ellipse is degenerated in a circle and the hyperbola is degenerated in a straight line (Fig.38).
TFCDs textures can be generated in the SmA liquid crystal confined between boundaries with different orientation, planar and homeotropic.