Patent ID: 7715073

Claim:
A hologram recorder in which coherent light from a light source is split into a signal beam and a reference beam, the signal beam is modulated by a spatial light modulator to be directed to a hologram recording medium, the reference beam is directed to the hologram recording medium to overlap with the signal beam for recording a hologram on the hologram recording medium, the hologram recorder comprising: a beam phase modulator including a plurality of optical devices each configured to assume one of two modes such as ON mode and OFF mode, the ON mode for causing the reference beam to be passed or reflected in a predetermined direction toward the hologram recording medium, the OFF mode for causing the reference beam to be blocked or directed in another direction other than said predetermined direction, each optical device providing a predetermined phase difference; and a phase modulation controller for individually controlling the optical devices to cause each of the optical devices to assume the ON mode or the OFF mode, thereby modulating the reference beam into a beam having a predetermined phase pattern.