Initialization-free dual-layer phase-change optical disk

For the rewritable dual-layer phase-change optical disk, before information is recorded on this disk, the initialization process that changes two phase-change recording layers from the as-deposited amorphous state to the crystalline state must be completed. However, the initialization process of a dual-layer disk, specially the second medium, is very difficult and the time required for the initialization process using a laser beam is significantly longer than for other manufacturing processes. In order to skip this bottleneck and shorten the production time in the product line, the initialization-free function of a dual-layer phase-change optical disk is attractive for the research and production of rewritable dual-layer phase-change optical disks. Our previous work (X.S. Miao et al, ODS´00, TuB3, 2000, and ISOM´01, Fr-K-05, 2001) demonstrated the initialization-free function for single-layer phase-change optical disks with GeSb₂Te₄ and Ge₂Sb_2+xTe₅ phase-change recording media. In this study, the design, simulation, fabrication and characterization of the initialization-free dual-layer phase-change optical disk were carried out.