The Configuration in a Ferroelectric Liquid Crystal Cell in Terms of a Rigid Chevron Structure

Abstract

Reorientation of the optic tensor configuration in a ferroelectric liquid crystal (FLC) cell is investigated under the application of a DC field. This is performed by the excitation of guided optic modes in a thin FLC layer. A careful analysis of the structure is performed by comparison of reflectivity data (showing the mode excitation) to theory for a variety of proposed models of the optic tensor profile. It is seen that the only way in which the data can be explained is by the retention of the chevron structure in the smectic layering under the application of a field. The FLC is seen to reorient within this structure for moderate fields, leaving a pinned point in the middle of the sample at the chevron cusp. This shows that simple models which allow the smectic layer structure to distort under field application are inadequate, and provides direct optical observation of the chevron structure.

Key Words:

• ferroelectric liquid crystal
• optic modes
• director profile
• chevron structure