| 摘要 |
PURPOSE:To give a high reflection factor to a medium in a wide wavelength area and to apply this medium to many optical drives by successively laminating first, second, and third recording layers on a substrate and providing the repeating unit of a two-layered laminated body so as to satisfy specific conditions. CONSTITUTION:The first recording layer 12 made of an organic matter, the second recording layer 13 made of an organic matter, and the third recording layer 14 made of an organic matter are laminated in this order on the substrate 11 to constitute an optical disk. The layer 12 satisfies the conditions of inequalities I. The layer 13 satisfies the conditions of inequalities II, and the layer 14 satisfies the conditions of inequalities III. In this inequalities, n1r, n2r, and n3r are respective real number parts of complex indexes of refraction for the reproducing layer wavelength of layers 12, 13, and 14 and k1r, k2r, and k3r are respective imaginary number parts of complex indexes of refraction for the reproducing laser wavelength of layers 12, 13, and 14. Thus, this medium has a high reflection factor in a wide wavelength area and can be applied to many optical drives. |
