Patent ID: 7803444

Claim:
An optical disk comprising: a substrate having lands and pits along a recording track where data can be recorded; a reflective film on the substrate; and a protective layer on the reflective film, wherein, the pits are such that when an edge of a pit is irradiated with light transmitted through the protective layer, the pit deforms such that pit data are rewritten and recorded, and the reflective film is an alloy formed of Al (100-x-y) Fe x X y , where Al is the main component, and X contains any one or more of Ti, Cu, Au, Pt, and Si, 3 ≦x≦15, 3 ≦y≦15, the reflective film has a thickness from 10 nm to 40 nm, the reflective film has a surface roughness Ra of 0.8 nm or less, and the reflective film exhibits a reflectance of 35% or more with respect to the Blu-Ray Disc standard when irradiated by laser light with a wavelength of 405 nm and a numerical aperture of 0.85.