Masaki Aoshima

Inorganic Write-Once Disc for High Speed Recording

We have developed an inorganic write-once disc based of the Blu-ray disc format. Our write-once disc has a double layer recording stack of a Cu alloy layer and a Si layer. These materials are environmentally friendly and low in cost. We designed a new write pulse strategy for high-speed recording while maintaining low recording peak power. As a result of using our write strategy, we obtained a jitter value of less than 8% with optimum recording power of 5 mW in the range of 36 Mbps to 144 Mbps.

Inorganic write-once disc with quadruple recording layers for Blu-ray Disc system

The optical disc with larger capacity and higher speed data recording rate will be required in coming broadband network society. We have developed the inorganic write-once disc with quadruple recording layers for the blu-ray system. We obtained the reflectivity of more than 5% and a jitter value of less than 10% for each recording layer. As a result, we proved the possibility of 100 GB user capacity of 120 mm diameter size.

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.