Abstract: An optical device according to this invention includes a phase modulating optical unit comprising a plurality of optically transparent base members each of which includes an optically transparent electrode and an alignment film formed in this order, and an optically transparent birefringent medium, wherein the optically transparent base members are spaced from one another at predetermined intervals so that the electrode and the alignment film of a base member is confronted to the electrode and the alignment film of another base member, and at least one kind of liquid crystal selected from the group consisting of ferroelectric liquid crystal (FLC), antiferroelectric liquid crystal (AFLC) and smectic liquid crystal having an electro clinic effect (SmA) (or mixed liquid crystals thereof) is injected into gaps between the base members.

Abstract: A liquid crystal device comprises a pair of substrates and a liquid crystal provided between the paired substrates wherein domains whose threshold voltages are different from one another are finely distributed throughout the liquid crystal. In particular, the respective substrates each has a transparent electrode and an alignment film formed thereon in this order and the substrates are assembled to establish a given space therebetween, and a ferroelectric liquid crystal being injected into the given space wherein domains are finely distributed as set out above, thereby providing a a liquid crystal display device. The fine distribution is such that when a transmittance through inverted domains is 25%, the number of domains (microdomains) having a size of larger than 2 .mu.m.phi. in a field of 1 mm.sup.2 is not smaller than 300, preferably not smaller than 600, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%.