Method of optimizing the write power for recording marks in an information layer of a record carrier and recording device using such an optimizing method

A method of optimizing the write power for recording marks in an information layer of a record carrier by irradiating the information layer with a (pulsed) radiation beam. The method includes recording a pattern of test marks including short marks having a predetermined short nominal runlength onto the record carrier by applying at least three different write powers; measuring the runlengths of the recorded short marks obtained by applying the at least three different write powers; and determining an optimum write power based of the deviations of the measured runlengths from the nominal runlength of said short marks.