THE CHARACTERIZATION OF TRACKING SERVO SIGNAL AND CROSS-TALK OF MAGNETO-OPTICAL DISKS WITH Cr GUIDING LAYERS

Abstract

Abstruct-Magneto-optical disks with metal guiding layers have spiral guiding bands which works as slits placed close to recording layers. The divided push-pull signal has been improved by using Cr as guiding layers. The disk noise for the track pitch of 0.85 !..lIn is lower than that of a pre-grooved glass disk with the track pitch of 1.6 J..lI1l. It is confirmed that the disk noise which arises at the edges of the spiral Cr guides is very small. The maximum CNR of 47.3 dB and 54.0 dB were obtained at 3.73 MHz and 1.0MHz for the track pitch of 0.85 J..lI1l. The magnetic domains are restricted in the recording regions because the cross-talk at 1.0 MHz has been suppressed to less than -23.4 dB even though the readout laser spot size is about 1.4 times as large as the track pitch.