| 摘要 |
PROBLEM TO BE SOLVED: To provide a phase transition type optical disk which is high in recording sensitivity and which is reproducible by a DVD-ROM drive. SOLUTION: On a substrate 101, first, second and third dielectric layers 102, 103, 104, a recording layer 105, a fourth dielectric layer 106 and a reflection layer 107 are successively laminated. The reflectivity of a disk is more than 45% when the recording layer 105 is in an amorphous state and not less than 3% and not more than 25% when it is in a crystalline state. In this way, as the recording sensitivity is kept high, high reflectivity is realized, the reproduction of recording information is made possible by a DVD-ROM drive. |
