Read/write characteristics of the magnetic amplifying magneto optical syste
m (MAMMOS) with alternative readout fields such as carrier to noise ratio (
C/N), eye pattern, jitter and bit error rate (BER), are investigated with a
640 nm wavelength laser diode and 0.55 numerical aperture of the objective
lens. The C/N value of 0.12 mu m is 50 dB and is independent of the mark l
ength. A very clear eye pattern was observed. The results show that the jit
ter value is less than 3% compared with the window width and it is only dep
endent on the switching speed of the readout field. The error rate is impro
ved by using a thin recording layer of 50 nm in thickness. The minimum doma
in length which yields a BER of less than 1 x 10(-4) is 0.045 mu m (45 nm);
the minimum space length is 0.10 mu m (100 nm). These results are confirme
d at a track pitch of about 0.40 mu m. By using a digital versatile disk (D
VD) pickup, the areal density can be estimated to be about 23 Gbit/in(2) wi
th the user data capacity of 30 GB/120 mm phi. By using a 400 nm blue laser
diode, these values are estimated as 59 Gbit/in(2) and 77 GB/120 mm phi.