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 ru
bbed, we found that the optic axis of the liquid crystal region close to th
e unrubbed substrate deviates from the rubbing direction less than the hulk
. in switching experiments we find that this region is also slower then the
bulk and it is virtually free from the undesired pretransitional effect. W
e also found an asymmetry in the switching of the surface region and we use
a simple model to account for it.