SYSTEM FOR GENERATING REFERENCE BEAM ANGLE CONTROL SIGNAL AND HOLOGRAPHIC INFORMATION RECORDING AND/OR REPRODUCING APPARATUS EMPLOYING THE SYSTEM

摘要

A system for generating a reference beam angle control signal and a holographic information recording and/or reproducing apparatus including the system are provided. When record of a two-dimensionally (2D) modulated signal beam superposed in the same volume of a holographic medium is called a book, the system includes: a first photo-detector and a second photo-detector arranged to detect signal beams reproduced from first and second adjacent books disposed on both sides of a specific book that is to be reproduced from the holographic medium; and a signal processing unit arranged to obtain a reference beam angle control signal for controlling the incident angle of a reference beam emitted to the holographic medium using a differential signal between output signals of the first and second photo-detectors.