Optical properties of the cartwheel cell

An examination of the characteristics of the cartwheel cell in the presence of an in-plane electric field using a three-dimensional mathematical model to simulate dynamic and static effects is presented. Electrode patterns are modelled that mimic the electrode patterns on the real device. The effect of applying an electric field to the cell, filled with a nematic liquid crystal, from a relaxed state is examined and the possible distortions in the liquid crystal that can be caused by the electric fringing field around the electrodes are noted. The overall direction of the electric field, produced from the voltages applied to each electrode, is rotated by varying the magnitude of the voltage applied to each electrode and the director patterns and defects produced are observed. Finally the retardation of light through the cell is modelled based on the assumption that, when relaxed, the twist in the cell is independent of the z-axis and comparison to experimental results are presented