Antiferroelectric liquid-crystal cells usually show symmetric electro-optic
switching response from the antiferroelectric state to two opposite ferroe
lectric states. Intermediate transmission levels (analog gray scale) can be
stabilized, applying a constant dc bias voltage after switching. Modifying
the manufacturing process and using narrow dynamic-range antiferroelectric
materials, a fully asymmetric response has been achieved. This asymmetric
switching allows the antiferroelectric cell to be driven as a ferroelectric
cell, reducing or eliminating the bias voltage, and ultimately leading to
analog optical multistability, i.e., devices whose optical transmission may
be arbitrarily set and maintained without power supply. (C) 2001 American
Institute of Physics.