Study of orientation of liquid crystal molecules at interface by shear horizontal wave

The director-orientation of a liquid crystal near an interface between a glass plate and a liquid-crystal layer is studied under propagation of a shear horizontal (SH) acoustic wave. An acoustic phase-delay of a SH wave device with various liquid-crystal director orientations, which is affected by the liquid-crystal director orientation, is measured. The fractional velocity change of the SH wave is related to the liquid-crystal director orientation by numerical analysis. The dependence of the phase-delay on the applied voltage to the liquid-crystal layer is evaluated. The present technique is useful for evaluating the liquid-crystal director orientation without requiring a complicated experimental setup.