| 摘要 |
PURPOSE: To obtain an excellent recording and reproducing system by controlling the distance t between information recording planes, the numerical aperture NA of an objective lens to introduce the light for reading to one of these planes, the wavelength λ of the light for reading, the equivalent refractive index n of each information recording plane, and the number i of the plane in laminated layers to satisfy a specified formula. CONSTITUTION: A light-reflecting layer 12 is formed on the surface of a substrate 11 by using vacuum vapor deposition device. Then the substrate is irradiated with radial rays from a transparent stamper side to cure a radiation-curing resin 14 on the reflection layer 12. After curing, the array of pits on the transparent stamper 13 is transferred to the resin 14. Then Si, Al and the like are vapor-deposited on the surface of the resin 14, where embossed pits, that is pits P2 are formed to form a reflection layer 15. Then a protective layer 16 is deposited thereon to obtain an optical disk. The distance t between information recording planes, the numerical aperture NA of the objective lens to introduce the light for reading to one of the planes, the wavelength λ of the light for reading, the equivalent refractive index of each information recording plane, and the number of the plane in the laminated layers are controlled to satisfy the relation of formula in order to obtain an excellent recording and reproducing system. |
