OPTICAL DISK AND METHOD OF MANUFACTURE THEREOF

摘要

A high-capacity optical disk, such as of 15 GB or greater, is provided. The optical disk comprises an optical disk substrate (3) on which lines of pits (2) corresponding to the record signals are formed; a reflective coating (4) covering the surface of the optical disk substrate (3) where lines of pits (2) are formed; and a transparent layer (5) formed on the reflective coating (4). For reading or reproduction, a laser beam of 350- to 420-nm wavelength is emitted through the transparent layer (5) on the surface to read the signals recorded as lines of pits. The pits are of 80 nm to 250 nm in length and width as viewed from the transparent layer side where the laser beam for reproduction is incident. The thickness of the reflective coating is less than 20 nm, for example, 8 nm or more.