| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical information recording/reproducing apparatus capable of reducing loss light, improving light utilization efficiency, obtaining reproduced data with high quality and achieving high-speed recording/reproducing, by using an optical element capable of performing high-speed control.SOLUTION: An optical information recording/reproducing apparatus utilizing an angle multiplexing recording type hologram, includes: a light source 1 for emitting a light beam; a branch part 10 for branching the light beam emitted from the light source into signal light and reference light; an angle variable part for changing an angle of the reference light to be made incident on an optical information recording medium 100; a spatial light modulation part 25 for adding information to the signal light; an objective lens for irradiating the signal light to the optical information recording medium; an imaging part 50 which, when the reference light is irradiated to the optical information recording medium, detects diffraction light generated from a recording area in the optical information recording medium; and an optical element 91 for shaping a shape of a light beam of the reference light. The optical element shapes the shape of the light beam of the reference light so that a beam diameter of the reference light in a multiplex direction is larger than a beam diameter of the reference light in a pitch direction. |
