title: All-optical switchable holographic Fresnel lens based on azo-dye-doped polymer-dispersed liquid crystals.
abstract: Fabrication of an all-optical switchable holographic liquid crystal (LC) Fresnel lens based on azo-dye-doped polymer-dispersed LCs is reported using a Michelson interferometer. It is found that, upon circularly polarized photoirradiation, the diffraction efficiency of the fabricated Fresnel lens was increased significantly in a reversible manner. We believe this is due to the anisotropy induced by reorientation of the LC molecules coupled with azo-dye molecule orientation due to trans-cis-trans photoisomerization, which modulates the refractive index of the LC-rich regions. We also studied the effect of azo dye on the polarization dependency of the fabricated lens.
authors.affiliation: Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Jashnsaz
authors.forename: Nahid Hosain
authors.initials: NH
authors.lastname: Nataj
authors.forename: Ezeddin
authors.initials: E
authors.lastname: Mohajerani
authors.forename: Amir
authors.initials: A
authors.lastname: Khabbazi