Multi-layer optical disc, information recording method and information reproducing method

摘要

Single-sided dual-layer recordable disc 100 may be used. Information recording is performed by forming mark and space portions on data area DA using modulated laser power. Pp denotes the maximum laser power or peak power for forming the mark portion, and Pb denotes the bias power for forming the space portion. Power ratio Pb/Pp is calculated (ST16) for each of recording layers L0 and L1. Information is recorded (ST14-ST22) on any of the recording layers L0 and L1 based on the result of calculation. Here, the calculated power ratio Pb/Pp changes among the recording layers L0 and L1, thereby optimizing the recording condition for a multi-layer recordable optical disc within relatively short time.