READ/WRITE CHARACTERISTICS OF ZERO FIELD MAMMOS

We have developed a magneto optical disk system, having the recording density of 7.1 Gbit/in2, by using zero-field type MAMMOS technology and an in-groove structured disk with a 635 nm laser diode and a 0.60 N.A.objective lens. We demonstrated that the system has enough margins for read/write powers, tilt, detrack anddefocus. On the other hand, the dependence of polarization direction of the incident beam on read/write characteristics was a problem, but was solved by optimizing the groove width.