MAGNETO-OPTICAL DISK AND MAGNETO-OPTICAL DISK SYSTEM

摘要

PURPOSE:To provide a magneto-optical disk reducing the total phase difference of the disk to a nearly zero level at the time of rotation at service rotation frequency and ensuring large amplitude of a magneto-optical signal. CONSTITUTION:A double refraction distribution at still time is imparted to a magneto-optical disk substrate so as to negate double refraction at the time of rotation at service rotational frequency as the total of double refraction due to centrifugal force at the time of rotating a disk and having a code (changing direction) determined by the direction of linearly polarized light in a driving optical system on a plane of polarization and the phase difference of a magneto- optical film. The amplitude of a magneto-optical signal at the time of rotating the disk can be made maximum.