Optical information recording medium, optical information recording/reproducing method, and optical information recording/reproducing device

摘要

An optical information recording medium in which the ranges of the refractive index and thickness of a protective layer in a case where the protective layer is constituted by a plurality of layers are newly specified and the refractive index and thickness of the protective layer are determined in these ranges, thereby ensuring that even if variation in thickness of the protective layer to ±3 mum is tolerated, spherical aberration in the optical information recording medium is substantially to within 30 mlambdarms.