| 摘要 |
<p>A write once optical recording medium in which the relative ratio of the write power to the read power can be set high, the stability of recording/recording can be maintained high at low cost. A recording layer (18) of a high-speed write-once optical recording medium (10) is a multilayer of first and second recording sub-layers (18A, 18B) containing a kind of metal, for example, Al and Sb, respectively. The ratio Pw/Pr between the write power Pw and the read power Pr for the optical recording medium of this structure ranges from 2.0 to 8.0. On applying a laser beam having a wavelength of 200 to 450 nm and a write power of 2.5 to 5.0 mW to the recording layer (18) at a recording transfer rate of 35 Mbps or more, Al and Sb contained in the recording sub-layers (18A, 18B) are diffused and mixed, thereby making a recording mark having a low reflectance, composed of a single layer, and changed irreversibly.</p> |
