| 摘要 |
<P>PROBLEM TO BE SOLVED: To record additional information by controlling a pit edge in a master disk exposure system which carries out the pulse light emission of a laser as a thermal recording method. <P>SOLUTION: Pit edge position control is not adjusted by the pulse timing of the laser, and the laser is made to emit light from a laser light source by regular pulse modulation without an edge change and the outputted laser is changed with the exposure power of only both ends of a pit by an optical intensity control means. Then, the change of the optical intensity of a pit edge is recorded as the change of a pit length (that is, the change of the edge position of the pit). As an optical intensity control means, a variation on optical intensity in the 0th diffracted light of an acousto-optical element (AOM) is controlled by controlling diffraction efficiency using the AOM, and further, the 0th diffracted light is shaped by a spatial frequency filter. The variation of the optical intensity is controlled by controlling polarization by using an electro-optical modulator (EOM) and separating polarization components with polarization component separating components such as polarization beam splitters (PBS). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
