Easily aligned deformable-helix ferroelectric liquid crystal mixture and its use in devices

Ferroelectric smectic C* liquid crystals have been shown to exhibit high speed, multistate electro-optic and display device applications, particularly when incorporated into the surface stabilized ferroelectric liquid crystal (SSFLC) light valve. The SSFLC geometry results in two distinct stable states. Unfortunately, the lack of intermediate electrically addressed states precludes a natural gray-scale effect. The recently discovered Deformed Helix Ferroelectric liquid crystal (DHFLC) effect opens the door to linear gray scale or linear phase modulation in a ferroelectric liquid crystal device on a microsecond time-scale. One drawback of currently available DHFLC materials is that their alignment quality is limited due to the lack of a nematic phase above their smectic A phase. While alignment can be improved by the use of shear techniques, this represents an undesirable option for a manufacturing process. We show that DHFLC mixtures can possess a nematic phase with a long N* pitch and tight C* pitch in the C* phase. These new easily aligned DHFLC mixtures are discussed as well as their use in beam-steering devices that can benefit from analog optical response.