OPTICAL DISK

摘要

An optical disk which comprises a recording layer and a light transmitting layer sequentially laminated on a substrate, and which records and/or reproduces information when a light beam is shone onto the recording layer via the light transmitting layer. The light transmitting layer in the optical disk is comprised of a laminate formed by laminating at least two material layers different in refractive index from one another, and spherical aberration, by an object lens that condenses a light beam used for recording/reproducing information, is set to be near a minimum value.