| 摘要 |
<p>A phase-change recording medium having a recording layer (4) made of a Ge-Sb-Te alloy, comprises an interface reflection control layer (3) provided on a laser beam irradiated side of the recording layer (4). The interface reflection control layer (3) has an attenuation coefficient k and a refractive index n, simultaneously satisfying the conditions of k≥0.22n+0.14, k≤0.88n-0.19, and n≤2.8. This restricts to a specified range the intensity ratio between the reflected wave from and the incident wave on the interface between the recording layer (4) and the interface reflection control layer (3). As a result, for the recording layer (4) the ratio (Ac/Aa) of the light absorption factor (Ac) in the crystal state to the light absorption factor (Aa) in an amorphous state increases. Furthermore, the optical contrast also becomes sufficiently high. It is therefore possible to produce a high quality reproduced signal in overwrite recording. Further, by providing a heat dissipation layer (7) between the interface reflection control layer (3) and the substrate (1), the mark edge recording at a high recording density can be performed with precision.</p> |
