BISTABLE ELECTROCHIRALLY CONTROLLED LIQUID CRYSTAL OPTICAL DEVICE

The present invention relates to a liquid-crystal optical device of the type comprising two transparent plates provided with drive electrodes and a liquid-crystal material placed between the plates, the molecules of which liquid crystal are capable of alternately occupying at least two stable states, in which chiral ions are dissolved in the liquid-crystal material, and electrical power supply means are provided capable of applying to the device pulses of electric field perpendicular to the plates oriented selectively in one direction or the other, characterised in that the electrical power supply means are designed to apply, in succession, to the device: - a drive signal capable of breaking the attachment of the liquid crystal on the plates and of inducing a generally homogeneous orientation of the liquid crystal, and then - a control pulse of smaller amplitude than that of the drive signal, and of polarity chosen depending on the final state required.