Optical data recording method

A data storage medium comprising a recording area on which a plurality of recording marks and spaces having lengths defined by a predetermined modulation method are formed by emitting a pulsed light beam to the data storage medium,

• wherein at least two of the plurality of recording marks comprise:
• a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark,
• the multi-pulse train has a pulse period longer than T, T representing a reference period of the recording modulation code,
• the number of pulses in each of the recording marks is increased by one as the recording mark is increased in length by 2 T,
• the plurality of recording marks have different lengths differing by T or multiples thereof from one another,
• the shortest recording mark and the second shortest recording mark are each constituted by a single pulse, and
• the third shortest recording mark and the fourth shortest recording mark are each constituted by two pulses,
• a last pulse rising timing an nth (n is an odd number which is three or greater) shortest recording mark and a last pulse rising timing of an (n+1)th shortest recording mark are different from each other by 0.5 T, and a last pulse rising timing of an (n+1)th shortest recording mark and a last pulse rising timing of an (n+2)th shortest recording mark are different from each other by 1.5 T,
• the multi-pulse trains of the plurality of recording marks have an equal pulse width with each other, and
• the multi-pulse trains of the plurality of recording marks have an equal pulse period with each other.