BISTABLE ELECTROOPTICAL SWITCHING IN THE SMECTIC I-STAR PHASE OF A FERROELECTRIC LIQUID-CRYSTAL

The ferroelectric switching behaviour of the highly ordered smectic I* phase has been investigated in the mixture which shows a S*I phase at room temperature. The bistability was obtained in a 3.5μm thick cell. Director switching and the reorientation processes have been studied by applying symmetric square and triangular wave pulses. It has been found that an asymmetric switching occurs in the smectic I* phase for low electric fields due to the hexagonal ordering of the molecules in the layer. This asymmetric switching was confirmed by optical microscopy and four stable states have been observed for low electric field. For higher electric fields only one state is stabilized which results in symmetric switching by both methods in the smectic I* phase. © 1990 Taylor & Francis Group, LLC.