| 摘要 |
PROBLEM TO BE SOLVED: To improve the repeatability of rewriting in a phase change optical disk as well as to inhibit cross erasure. SOLUTION: A 1st dielectric layer 11, a 2nd dielectric layer 12, a 3rd dielectric layer 13, a recording layer 15, a 4th dielectric layer 14 and a reflecting layer 16 are successively laminated on a substrate 10. The refractive index n1 of the 1st dielectric layer 11, the refractive index n2 of the 2nd dielectric layer 12 and the refractive index n3 of the 3rd dielectric layer 13 satisfy the relations n1>n2 and n3>n2. Since the reflectance of the amorphous part can be increased and the absorbance of the amorphous part can be reduced, cross erasure can be inhibited. Since a light absorbing layer is not present between the substrate and the recording layer, a temperature rise near the surface of the substrate is inhibited, the thermal deformation of the substrate is suppressed and repeatability can be improved. |
