Photochromic diarylethenes for three-wavelength optical memory

For the first time, we carried out successfully three-wavelength photon-mode optical storage using photochromic diarylethene materials, 1,2-bis(2-methyl-5-hydroxymethyl-thien-3-yl)perfluorocyclopentene (1a), 1,2-bis(2-methyl-5-(4-N,N-dimethylaminophenyl)-thien-3-yl)perfluorocyclopentene (2a) and 1,2-bis(2-methyl-5-(2,2′-dicyanovinyl)-thien-3-yl)perfluorocyclopentene (3a), as recording medium. Three laser beams of 532, 650 and 780 nm were used in recording and readout simultaneously, and signals with high S / N ratio were obtained. The results showed that the three diarylethenes had responded rapidly upon irradiation of the corresponding wavelength laser. Especially there was no crosstalk existing in each one of them. The destruction of the readout and the photochromic properties of the three diarylethenes in PMMA films were also investigated.