Inorganic write-once disc for high speed recording

Write-once media has been used as storage media for medical data, official documents in order to prevent tampering. In addition, write-once media, such as CD-R or DVD-R are the most popular storage media for the computer in the world by reason of the interchangeability with the ROM disc. On the other hand, in order to obtain much larger capacity, DVR-blue system (/spl lambda/ = 405 nm, NA = 0.85) has been proposed. Many storage media, such as rewritable discs, write-once discs, ROM discs have been developed to apply this system. We have already reported high speed rewritable disc for this system. We have developed write-once disc for this system, too. And we have achieved wide data recording rate in the range of 35 Mbps to 140 Mbps on a disc with inorganic recording material. In this report, we show the read and write characteristics of the write-once disc with inorganic write-once material.