Surface evanescent field characterisation of antiferroelectric liquid crystals

In this paper we report a study of the dynamics of antiferroelectric liquid crystals by using simultaneous total internal reflection and transmission. In devices having both substrates coated with a polyimide, but only one rubbed, we found that the optic axis of the liquid crystal region close to the unrubbed substrate deviates from the rubbing direction less than the bulk. In switching experiments we find that this region is also slower then the bulk and it is virtually free from the undesired pretransitional effect. We also found an asymmetry in the switching of the surface region and we use a simple model to account for it.