Reflective optically active diffractive device

PATENT STATUS: GrantedA reflective liquid crystalline diffractive light valve for use in a diffractive projection system. The liquid crystal cell includes a transparent substrate and a reflective substrate treated to provide alternating stripes which cooperate with the liquid crystal to form liquid crystal domains extending acros the thickness of the cell that will produce an appropriate phase difference in light reflected by the cell, irrespective of the polarization of incident light. The techniques embodied in the present invention are applicable to the creation of electrically controllable diffractive optical elements for ray optic, integrated optic or fiber optic utilization operated in either transmission or reflection. Diffractive patterns may be lithographically, holographically or interferometrically generated.