Compact Magneto-Optical Disk for Coded Data Storage

A compact magneto-optical disk drive compatible with current optical disk systems is reported. A tracking detection system enabling use with add-on (non-erasable) optical disks was adopted. High-speed accessing was accomplished by constructing the head from both stationary and moving mechanisms. Noise analyses showed that for large analyzer angles θ
_A
, N
_disk
≫ N
_laser
≫ N
_shot
, but when the SN ratio was maximum at θ
_A
~ 10°, the three noise levels were roughly equal.