An optical device is provided which has a light converging unit for converging
the light illuminated on a magneto-optical recording layer of an optical recording
medium and a magnetic field generating unit provided on the light converging unit
towards the optical recording medium. The diameter of the light beam radiated on
the magneto-optical recording layer of the optical recording medium is controlled
by a light transmitting hole of the magnetic field generating unit. The light beam
illuminated on the magneto-optical recording layer of the optical recording medium
is not fluctuated in diameter so that it is possible to produce a magnetic field
at a low power consumption. In addition, the magnetic field generating unit is
not liable to be ruptured. There is also provided a recording and/or reproducing
apparatus employing this optical device.
