A method for recording data in an optical recording disc including a
substrate and a recording layer formed on the substrate and containing a
phase change material as a primary component is constituted so that data
can be recorded therein and data recorded therein can be erased by
projecting thereonto at a high linear velocity equal to or higher than a
predetermined linear velocity a laser beam whose power is modulated in
accordance with a pulse train pattern including a plurality of kinds of
unit pulse train patterns each having at least recording pulses whose
levels are set to a recording power and bottom pulses whose levels are
set to a bottom power onto the recording layer and forming a plurality of
recording marks having different lengths in the recording layer, wherein
among the plurality of kinds of unit pulse train patterns used for
forming recording marks having different lengths those other than the
unit pulse train pattern used for forming the shortest recording mark are
determined so that they include recording pulses in a number
corresponding to the length of the recording mark to be formed, that
corresponding recording pulses included therein have a common pulse width
and that each of them includes a bottom pulse whose pulse width is
determined in accordance with the length of the recording mark to be
formed at the end thereof. According to this method for recording data in
an optical recording disc, it is possible to reduce jitter of a
reproduced signal even when data are recorded at a low linear recording
velocity in the recording layer designed to be suitable for recording
data therein at a high linear recording velocity.