Three-dimensional optical recording on a polyester film having photochromic thioindigo moieties in the main chain

Three-dimensional optical recording with confocal microscopy was carried out. As the recording medium, a polyester film having fluorescent photochromic thioindigo moieties in the main chain was used. Upon irradiation with focused 568 nm light from an Ar-Kr laser, the fluorescent trans forms in the film were converted into lion-fluorescent cis forms. The small recorded regions were detected as dark spots by using the same laser as:the reading light source. The size of the dark spots was approximately 300 nm in width and 1.5 mu m in depth, which corresponds to a recording density of more than 5 Gbit/mm(3).