Processing method of a master disc for optical discs and processing method of grooves

摘要

Provided is a processing method of a master optical disc with an improved jitter and modulating degree of the reproduced signal, and a fine reading accuracy. In an exposure step for forming one pit by laser beam exposure of a plurality of pulse arrays, using the laser beam for exposure to an optical disc as an intermittent beam, the pulse length of the edges of a pit is made longer than the pulse length of the center portion. Moreover, the pulse interval behind the front edge pulse and/or the pulse interval in front of the rear edge pulse is longer than the pulse interval of the center portion.