Optical information recording/reproducing apparatus

An optical information recording/reproducing apparatus, applying hologram of a angle multiplex recording method therein, comprising:

• a light source, which is configured to emit a light beam thereform;
• a divider unit, which is configured to divide the light beam emitting from the light source into a signal beam and a reference light;
• an angle variable unit, which is configured to change an angle of the reference light incident upon an optical information recording medium;
• a spatial light modulator unit, which is configured to add information to the signal beam;
• an objective lens, which is configured to irradiate the signal beam upon the optical information recording medium;
• an image pickup unit, which is configured to detect a diffracted light generating from a recording region within the optical information recording medium, when the reference light is irradiated upon the optical information recording medium;
• and
• an optical element, which is configured to shape a form of light flux of the reference light, wherein
• said optical element shapes up the form of light flux of the reference light, so that a light flux diameter of the reference light in a multiplex direction comes to be larger than the light flux diameter of the reference light in a pitch direction.