Optical Phase Change Disc without Bulk Laser Initialization and a Quick Bulk Initialization Structure

Optical phase change discs without bulk laser initialization were produced. 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 of 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 overwriting properties of the discs without bulk laser erasing were estimated. The recording jitter of the 1–7 frequency modulation signal increased during the first 2 or 3 overwriting iterations and then saturated 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 initialized at the overwriting speed.