Development of 40 GB dual-layer rewritable HD DVD media
Yasuhiro Satoh, Tsukasa Nakai, Sumio Ashida · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
We have developed a single-side dual-layer rewritable HD DVD media having a larger capacity of 40 GB (20 GB per layer) for the optical system with the NA of 0.65 and the wavelength of 405 nm, and achieved the good recording characteristics. For both layers, the same track pitch of 0.34 μm as HD DVD-RAM was used. We applied more accurate thermal analysis to the dual-layer rewritable media. It was expected that the effect of the cross-erase was very small. By optimizing thermal balance of dual-layer media, the good recording characteristics were obtained for both layers with enough tilt margins. The feasibility of the dual-layer rewritable media of 40 GB user data capacity was shown for HD DVD system.