Patent ID: 8570460

Claim:
An optical device comprising: a light source; an optical cell arranged to receive light from the light source, the optical cell containing a polymer-stabilized liquid crystal material including a substantially randomly oriented short-pitch cholesteric liquid crystal material having a pitch of less than 500 nm stabilized by a polymer material wherein (i) a concentration of the polymer material in the polymer-stabilized liquid crystal material and (ii) a highly twisted structure of the randomly oriented short-pitch cholesteric liquid crystal material cause the optical medium to interact with light received from the light source in a substantially polarization-independent manner and wherein the polymer material is less than about 25 wt-% of the polymer-stabilized liquid crystal material, the optical cell including electrodes for selectively applying a voltage across the polymer-stabilized liquid crystalline optical material; and a voltage source arranged to apply voltage to the electrodes over an operative voltage range wherein the optical cell provides polarization-independent phase retardation as a function of voltage over the operative voltage range, the operative voltage range being not sufficient to switch the optical cell into a homeotropic state, the randomly oriented short-pitch cholesteric liquid crystal material remaining randomly oriented over the operative voltage range.