Study On The Polarization Holographic Charicteristics Of Photochromic Polymer Films

In the past decades, organic photochromic materials doped azo polymer medium have attracted considerable interest in optical storage owing to the rewritable, high-resolution and low cost outstanding characteristics. The photoinduced anisotropy, polarization holography and polarization holographic storage in Methyl orange doped polyvinyl alcohol films were described in this paper.At first, the development of information storage is introduced. Great convenience is brought to the people’s life by information storage. Information storage is developed towards to high density, high quality, high speed and high integration. Then, the theory of polarized light field and the polarization holographic theory were analyzed. Further, the photoinduced birefringence of the methyl orange doped polyvinyl alcohol polymer is investigated. Transmittance versus time was studied. Thermal erasure and light erase transmittance were also investigated. The experimental results were analyzed by theoretical fitting respectively. The results show that thermal erasure process is not complete compared to the light erasure.Based on photoinduced birefringence, polarization holographic recordings and polarization holographic storage was accomplished in Methyl orange doped polyvinyl alcohol. Pure polarization gratings are recorded by two Nd:YAG laser beams with S-S、S-P and LCP-RCP polarizations. The experimental results are analyzed by theoretical fitting, which show that the diffraction efficiency of LCP-RCP is the biggest. Further, the influence of the detecting light polarization state on diffraction efficiency was studied.