Patent ID: 6914647

Claim:
An electrically drivable light modulator comprising: at least two liquid crystal layers for enclosing between at least two transparent plates having a surface anisotropy for orienting molecules of the at least two liquid crystal layers and having electrodes for generating an electric field in the at least two liquid crystal layers; wherein: the at least two liquid crystal layers include helical, smectic, ferroelectric liquid crystals, whose fast optical axes and slow optical axes, respectively, are disposed in parallel with a respective one of the at least two liquid crystal layers, and whose average optical anisotropy is influenceable by an action of the electric field; the at least two liquid crystal layers are situated one behind another in a path of rays of a light beam to be modulated; and directions of the fast optical axes and slow optical axes, respectively, of the at least two liquid crystal layers are rotated relative to one another so as to maintain that a polarization of the light beam upstream of the modulator is the same as a polarization of the light beam downstream of the modulator.