Holographic recording and reproducing using a compact configuration provides
no reduction in the recording/reproducing capability. Information light and recording-specific
reference light having a spatially modulated phase are generated and projected
onto an optical recording medium coaxially that converge on a reflecting surface
of a recording medium. P-polarized recording-specific reference light and S-polarized
information light are each optically rotated by a two-way split optical rotation
plate in directions different between respective half areas of the cross section
of the beam thereof. An interference paffern resulting from interference between
information light yet to impinge on the reflecting surface and recording-specific
reference light reflected by the reflecting surface and an interference pattern
resulting from interference between recording-specific reference light yet to impinge
on the reflecting surface and information light reflected by the reflecting surface
are recorded in the information recording layer.