| 摘要 |
PURPOSE:To form adequate pits by providing a circular substrate and recording layer which is laminated on said substrate, is constituted of at least two kinds of materials, and is changed in the comsn. ratio of said materials along the diametral direction of the substrate. CONSTITUTION:The substrate 22 is made of a transparent resin such as polycarbonate or transparent glass and the recording layer 23 is changed in the optical characteristics and shape by the application of thermal energy of a laser beam to be spot-radiated thereto, by which an optical disk 21 is formed. This recording layer 23 is constituted of the thin film such as GeTe film or TeSe consisting of a binary or more element alloy or compd. The compsn. ratio (content) of the materials constituting such film is changed along the radial direction of the substrate 22. The film is formed of such compsn. ratio at which the sensitivity (recording sensitivity) to cause the optical characteristics or shape to be changed by the application of the thermal energy is increased toward the outside peripheral part (arrow b) of an optical disk 21. |
