| 摘要 |
PURPOSE:To significantly improve the recording density by successively forming a first magnetic layer consisting of a rare earth metal-transition metal alloy, second magnetic layer, and third magnetic layer in such a maner that the first and third magnetic layers have perpendicular magnetic anistropy. CONSTITUTION:When a temp. rising area moves from the intraplane magnetization to the perpendicular magnetization, only the temp. rising part shows polar Kerr effect, and information is reproduced according to the reflected light from this part. To reproduce the successive recording pit by scanning a beam, temp. of the previous reproduced is decreased from the perpendicular magnetization to the intraplane magnetication and the pit shows no Kerr effect. Namely, magnetization recorded in the first magnetic layer 3 is covered with intraplane magnetization of the zero magnetic layer 3 and can not be read out. Thereby, mixing of signals form adjacent pits is prevented, and thereby, reproducing of smaller recording pits can be done and recording density is improved. |
