126.	Holographic twisted nematic gratings recorded in azo-dye doped liquid crystals with homogeneous alignment, T. Sasaki, H. Ono and N. Kawatsuki, Jpn. J. Appl. Phys. 46 (2007) 1579-1584.

Abstract

Twisted nematic gratings, originating from three-dimensional photoalignment of mesogenic molecules, have been recorded in azo-dye-doped liquid crystals by a polarization holographic technique. The three-dimensional distributions of the director were extensively investigated by considering the photoalignment of the azo-dye molecules and the resulting diffraction properties of the recorded gratings. The three-dimensional distributions of the director corresponded to the polarization modulation caused by light interference and to the propagation in liquid crystals with uniaxial optical anisotropy. These results suggest that the diffraction properties of the gratings can be controlled by the initial orientation of the liquid crystals and the polarization states of the recording beams.