Abstract
Rewritable optical recording has been demonstrated in a ferroelectric liquid crystal (FLC) with the chiral nematic (N*)-chiral smectic C (SmC*) phase sequence. In a homogeneously aligned cell surface-treated for a unidirectional molecular alignment, there are two kinds of layer configurations in the SmC* phase which appears directly from the N* phase with decreasing temperature. The direction of the layer alignment can be controlled by selecting the polarity of the applied electric field at the phase transition from N* to SmC*. Due to these characteristics, by irradiating a laser beam on a spot in the FLC in the SmC* phase under a specific polarity of the applied field, the layer alignment in the irradiated spot can be switched to the desired direction. This recording of the laser spot is erasable. In this device, the subtraction function in a binary image has also been realized.