Acoustooptic Effects of Nematic Liquid Crystals Induced by Elastic Wave Propagating in Glass Substrate

An elastic wave delay line with a glass plate as a propagation medium is investigated in relations to acoustooptic effects of nematic liquid crystals. A nematic liquid crystal cell is mounted on the central region of a glass plate for elastic wave propagation. The elastic wave propagating in the glass plate interacts with the liquid crystal in a wide frequency range. Two types of periodical domain structures are observed in the nematic liquid crystal cell under the existence of the elastic wave. One exists in both homeotropically and homogeneously aligned cells, and depends not on the kind of liquid crystal but on the carrier frequency of the elastic wave. The other is recognized only in homogeneously aligned cells and depends on the layer thickness and the kind of liquid crystal, but not on the carrier frequency of the elastic wave. Both periodical domain structures are induced by the elastic wave propagating in the glass plate.