| 摘要 |
PURPOSE:To make the influence of preheating effect due to the past optical pulse constant without changing the peak value of the optical pulse corresponding to a pit to be recorded. CONSTITUTION:In the optical pulse waveform with which a recording medium, is irradiated, a bias pulse light emitting part 1 with power level PB, pulse width WB, and pulse number NB less than a medium characteristic change level Pth is provided just before the end part of the light emitting part corresponding to the pit to be recorded. In the light emitting part, a pulse superimposing part 2 changing one part of which in the range of more than Pth to the pulse shape of lowest light emitting power level PP, pulse width WP, and pulse number NP is provided. The information is recorded by irradiating the recording medium with optical pulse and changing the medium characteristic using the thermal energy of the optical pulse. |
