Synthesis of a New Photochromic Diarylethene and its Application in Holographic Optical Storage

A new unsymmetrical photochromic diarylethene, 1-[2-methyl-5-(4-methylphenyl)-3-thienyl]-2-[2-methyl-5-(4-methoxylphenyl)-3-thienyl] perfluorocyclopentene (1a), was synthesized, and its photochromic properties were investigated. The compound exhibited good photochromism both in solution and in PMMA film with alternating irradiation by UV/VIS light. Upon irradiation with UV light, the colorless open-ring isomer 1a turned blue both in hexane and in PMMA film, and the maxima absorption of its closed-ring isomer 1b are 582 and 598 nm, respectively. In hexane, the cyclization/cycloreversion quantum yield of this diarylethene is 0.61/0.031. Using diarylethene 1b/PMMA film as recording medium, four types of polarization and angular multiplexing holographic optical recording were performed perfectly. For different types of polarization recording, the results demonstrated that the parallel circular polarization recording is the best method for polarization holographic optical recording when this compound was used as recording material. With angular multiplexing recording technology, two high contrast holograms were recorded in the same place on the film with the dimension of 0.78 mum².