Patent ID: 7859972

Claim:
A holographic optical information recording/reproducing device, comprising a coherent light source; and a beam splitting portion for splitting a light from the coherent light source, wherein: one of light beams split by the beam splitting portion becomes a beam array modulated and arrayed by a spatial light modulating element, the beam array serving as a signal light, the other light beam split by the beam splitting portion becomes a reference light, the signal light and the reference light intersect in a recording medium to generate interference fringes and the interference fringes are recorded as holograms in the recording medium at the time of recording information; only the reference light is irradiated to the recording medium and a diffracted light generated in the recording medium is detected by a light receiving element at the time of reproducing information; and the power of the reference light in the recording medium for information reproduction is larger than a sum of the power of the reference light and the power of the signal light in the recording medium for information recording.