1,2-Bis(2-methylbenzo[ b]thiophen-3-yl)perfluorocylopentenes undergo thermally irreversible photochromic reactions in which colouration/decolouration cycles can be repeated more than lo4 times without significant loss of perform a nce.

No abstract

A new type of photochromic compounds, diarylethenes with heterocyclic rings, has been developed for optical data storage media. Attention was focused to design and synthesize photochromic compounds with sensitivity at diode laser wavelengths and gated photochemical reactivity.

A new fluorinated holographic recording material is applied with a view to realizing holographic information system (HIS) media that offer high multiplexing numbers and high recording sensitivity. We report here, for the first time, the successful recording and reconstruction of 750 multiplexed holograms on a 50 Â 50 mm 2 photopolymer coupon sample based on a novel fluorinated holographic recording material for collinear holography. The proposed material yields bit error rates (BERs) less than 10 À2 in the X -Y plane of the coupon sample and thus is suitable for 532 nm optical data storage. It's fundamental properties, such as the relationship between BER and number of holograms, are determined. This new fluorinated material offers improved error maps as evidenced by the 0.4-mm-thick, 120-mm-diameter photopolymer disc. The average error rate is 1.61% for the disc sample. This new material successfully stored and reproduced a short segment of animated video data.

No abstract