Superlattice-like phase change optical disk for multispeed recording

Recently, we proposed the concept of superlattice-like (SLL) phase change optical disk and demonstrated excellent high-speed recording properties for disks adopting this SLL structure (T.C. Chong et al, Jpn. J. Appl. Phys. vol. 39, p. 737, 2000, and J. Appl. Phys. vol. 91, 2002). This technology paves an alternative way to develop phase change materials for optical disks. On the other hand, with the development of DVD technology, DVD recording is being introduced in two different markets simultaneously, i.e., the DVD video recorder and the DVD writer for personal computer use. It is expected that the recording speed of rewritable DVD media should be like the rewritable CD, which is compatible with CD writers with different speeds. Therefore, it is necessary to develop rewritable DVD media to cover a broad range of recording speeds in order to make them compatible with different DVD recorders and drives. In this contribution, we present recent progress on the recording properties of the SLL disk at different recording speeds by tuning the stack structure, aiming to make the SLL disk multispeed compatible.