Polarization gratings in twisted-nematic liquid-crystal composites doped with azobenzene dye.

Highly efficient and functionalized polarization gratings have been recorded in azobenzene-containing mesogenic composites with twisted nematic cell configurations. The polarization gratings formed in azobenzene-containing mesogenic composites show a high diffraction efficiency of more than 45% and convert the polarization state of light at the same time. The polarization direction of the diffracted laser beams can be controlled by the twisted angle of the nematic cell. These characteristics of the polarization gratings are well explained by means of Jones calculus.