ABSTRACT
Polarization gratings have been recorded in a combined liquid crystal (LC) cell made of a substrate covered with a photosensitive chalcogenide orientation layer and a reference substrate covered with a rubbed polyimide film. The gratings are formed due to the spatially modulated light-induced easy orientation axis on the chalcogenide surface recorded by two beams with opposite circular polarizations. The gratings are permanent, but they can be erased by one of the recording beams and re-recorded. The diffraction intensity of the circularly polarized light is achromatic and does not depend on the birefringence of the LC. The diffraction efficiency of the grating is of the order of a few percents. Application of an ac field causes a strong increase of the diffraction efficiency up to 45%.
