UNIFORM ROTATION OF SMECTIC LAYERS OF A FERROELECTRIC LIQUID-CRYSTAL IN AN ASYMMETRIC ELECTRIC-FIELD

An asymmetric ac electric field with amplitude E = 10 V/mu m gives ris e to a matched rotation of the normal to the smectic layers, while a s inusoidal field E = 1 V/mu m is used to study the rotation in the meth od of modulation total internal reflection ellipsometry, which makes i t possible to probe the region of a ferroelectric liquid crystal (FLC) next to the electrode (h approximate to 0.7 mu m). It is shown that t he angle of rotation of the normal to the smectic layers near the surf ace of the electrode varies reversibly as a function of the polarity a nd number of electric pulses applied, just as in the interior region. The characteristic dynamic properties of thin layers of nematic liquid crystals, such as an anomalously long relaxation time and a high-freq uency relaxation process, are observed in thin FLC layers. (C) 1998 Am erican Institute of Physics. [S0021-3640(98)01711-3].