We demonstrate polarization-independent holographic gratings (PIHGs) based on azo-dye-doped polymer-dispersed liquid crystal films. The PIHGs are recorded by irradiation under an intensity-modulated interference field, generated by two linearly polarized green optical beams, and by simultaneously applying a suitable AC voltage to the sample. The photoexcited azo dyes are adsorbed onto the UV-cured polymer film with their long axes parallel to the normal of the substrate. When the applied voltage is switched off, the PIHGs are generated with periodic modulation of liquid-crystal structures with transparently homeotropic and randomly scattered alignments. Additionally, the generated PIHGs can be completely switched off by an applied voltage.
© 2010 Optical Society of America
Diffraction and Gratings
Original Manuscript: October 22, 2009
Revised Manuscript: December 4, 2009
Manuscript Accepted: December 4, 2009
Published: January 8, 2010
Andy Ying-Guey Fuh, Che-Chang Chen, Ko-Ting Cheng, Cheng-Kai Liu, and Wei-Ko Chen, "Polarization-independent holographic gratings based on azo-dye-doped polymer-dispersed liquid-crystal films," Appl. Opt. 49, 275-280 (2010)