OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS, OPTICAL INFORMATION REPRODUCING APPARATUS, AND OPTICAL INFORMATION RECORDING MEDIUM

摘要

An optical information recording/reproducing apparatus includes an irradiation optical system of an information beam to an optical information recording medium that can record information as hologram by using interference fringes produced due to interference between the information beam that carries the information and a reference beam; a first light-reducing element placed in an optical path of the irradiation optical system of the information beam and reduces light intensity of part of the information beam; a detector that detects a reproduction beam emitted from the optical information recording medium; and a second light-reducing element placed in an optical path of the reproduction beam extending from the optical information recording medium to the detector, and that reduces light intensity of the reproduction beam emitted from a first area other than a second area, in which information is recorded with the information beam of which light intensity is reduced by the first light-reducing element.