OPTISCHES AUFZEICHNUNGSMEDIUM

摘要

An object of the invention is to write-once record and reproduce, or only reproduce, a mark smaller than the resolution limit; obtain a high level of reproduction performance (CNR and the like); and realize a high level of reproduction durability. In the invention, between a signal reproducing functional layer composed of Sb or Te and a protecting layer there is introduced a thermally stable diffusion preventing layer, and thereby reactions between the signal reproducing functional layer and the protecting layer due to increased temperature can be prevented or suppressed while increasing reproduction durability.