OPTICAL-PHASE CHANGE DISC WITHOUT BULK LASER INITIALIZATION AND A QUICK BULK INITIALIZATION STRUCTURE

Optical phase change discs without bulk laser initialization were prod uced. When an Sb film was partially separated by more than 7 nm from a V added Ag-In-Sb-Te alloy film, the as-deposited reflectivity oi. the disc was almost the same as that of a disc with an initial alloy film after annealing by bulk laser erasing. Further, the recording and ove rwriting properties of the discs without bulk laser erasing were estim ated. The recording Jitter of the 1-7 frequency modulation signal incr eased during the first 2 or 3 overwriting iterations and then saturate d at less than 3.5 ns until 30,000 overwriting iterations at a linear constant velocity of 12 m/s, Additionally, the disc could be initializ ed at the overwriting speed.