Polarization Patterns Hide and Display Using Photoinduced Anisotropy of a Novel Photochromic Diarylethene

A new unsymmetrical photochromic diarylethene, 1(2-methyl-5-(3-methylphenyl)-3-thienyl)-2-[2-methyl-5-(3fluorophenyl)-3-thienyl]-perfluorocyclo-pentene (1a), was synthesized and its photochromic and fluorescent properties were investigated. Diarylethene la changed the color from colorless to blue upon irradiation with 313 nm UV light, in which absorption maxima were observed at 579 nm in hexane and at 593 nm in PMMA amorphous film, respectively. The cyclization and cycloreversion quantum yields of la in hexane were determined to be 0.44 and 0.017. This new photochromic system also exhibited remarkable fluorescence intensity both in solution and in PMMA film. Using diarylethene 1c/PMMA film as recording medium and a linearly polarized 633 nm laser diode for recording and readout, polarization multiplexed image recording can be carried out in this film. The results demonstrated that the compound was very sensitive responding to 633 nm recording laser, and the recorded holographic images have good contrast, which illustrated that the diarylethene can be potentially used as holographic optical recording medium.