Investigation of multiple holographic recording in azo-dye-doped nematic liquid-crystal film

We report multiple holographic recording and optical address recognition schemes in Methyl Red-doped liquid-crystal film without an applied electric field. Ten gratings are recorded at a single location of a 5 mm2 area by using optical multiplexing methods, and the diffraction efficiencies are studied for multiplexed gratings. Diffraction behavior of angular and peristrophic multiplexed gratings is discussed, and two methods that involve recording angles and peristrophic rotation angles are presented for optical recognition.