Patent ID: 7808876

Claim:
A hologram recording/reconstructing apparatus that illuminates a hologram recording medium with a signal beam and a reference beam to record data thereon as a hologram, illuminates the hologram recorded on the hologram recording medium with a reconstruction beam to obtain a diffracted beam, and reconstructs the recorded data from the diffracted beam, the hologram recording/reconstructing apparatus comprising: a spatial modulator in which a reference beam region for generating the reference beam and a reconstruction beam region for generating the reconstruction beam are formed; and a controller configured to control a range of the reference beam region and a range of the reconstruction beam region, wherein, according to a temperature of the hologram recording medium during recording, the range of the reference beam region is set to a first predetermined range and thereby a range of an incident angle of the reference beam on the hologram recording medium is set to a first predetermined angle range; and according to a temperature of the hologram recording medium during reconstruction of the recorded data, the range of the reconstruction beam region is set to a second predetermined range and thereby a range of an incident angle of the reconstruction beam on the hologram recording medium is set to a second predetermined angle range.