Abstract: In a method of recording and reading optical information in a recording medium using holography, a first recording operation is performed for recording optical information in a first recording region in an overlapping manner by allowing a reference beam and a signal beam with data loaded to interfere with each other in the first recording region, the reference beam being angularly multiplexed at predetermined intervals. Furthermore, a second recording operation is performed for recording optical information in a second recording region adjacent to the first recording region in an overlapping manner by allowing the reference beam and the signal beam to interfere with each other in the second recording region, the reference beam being angularly multiplexed between the predetermined intervals. Consequently, optical information can be recorded so as to easily detect and determine a selected reproducing beam, thus increasing the reading efficiency of the optical information.

Abstract: An optical information reproducing apparatus using holography is provided. The holographic optical information reproducing apparatus includes an objective lens irradiating a reference beam to a predetermined position on a recording medium and receiving a reproducing beam reproduced from the recording medium, an optical information detector detecting the reproducing beam passing through the objective lens, a driving unit changing a distance between the optical information detector and the objective lens and an image adjusting unit adjusting magnification and a focus between an output image resulting from the reproducing beam passing through the objective lens and a detected image detected by the optical information detector with a variation in distance between the optical information detector and the objective lens.

Abstract: An optical information processing apparatus and an optical information processing method are provided. The optical information processing method includes steps of: irradiating a reference beam on an optical information recording medium having a plurality of recording regions which are disposed in a track direction to be adjacent to each other so as to enclose a specific recording region and first and second recording regions adjacent to the specific recording region; separating a readout beam reproduced from the specific recording region from the first and second neighborhood readout beams reproduced from the first and second recording regions by using the reference beam; and detecting intensities of the first and second neighborhood readout beams and comparing the intensities of the first and second neighborhood readout beams to calculate an optical information reproducing error.