Abstract

The possibility of the forced generation of regular hydrodynamic convective motions in a nematic liquid crystal with homeotropic boundary conditions and under the action of the radiation pressure of an acoustic wave with a periodic transverse intensity distribution are investigated theoretically. The excitation mechanism is as follows. Two interfering acoustic waves are partially absorbed by the liquid crystal. The absorption of an acoustic wave with a spatially periodic intensity distribution produced the same transverse distribution of the radiation pressure acting on the nematic particles. These forces generate steady convective motions of the liquid, whose velocity gradients cause the nematic molecules to rotate. If acoustic waves are absent and the nematic is placed between crossed polarizers, it is opaque to a light wave in normal incidence on the layer. The reorientation of the nematic director creates ordinary and extraordinary light waves, so that the field of view is cleared periodically in space.

© 1994 IEEE