Superresolution optical disk with a thermoreversible organic thin film.

Recording and retrieving small marks far beyond the optical diffraction limit in a high-speed rotating phase-change optical disk have been investigated by use of a thermoreversible organic thin film as a superresolution mask layer. The organic thin film exhibited significant thermoreversibility and rapid response on laser irradiation. Recorded marks as small as 120 nm in length could be detected by a dynamic disk tester with a laser wavelength of 635 nm and a numerical aperture of 0.6.