Patent ID: 8416480

Claim:
A hologram reproducing apparatus comprising: a first reference light path leading laser light from a laser light source so that a hologram recording medium is irradiated with first reference light; a diffracted light path leading diffracted light, generated from the hologram recording medium by irradiation with the first reference light, to a beam splitter, wherein the beam splitter bends the diffracted light and directs the diffracted light to a light receiving element having a plurality of pixels; a second reference light path leading second reference light, having the same polarization direction as that of the diffracted light, from the laser light source through the beam splitter and to the light receiving element such that interference of the second reference light and the diffracted light is realized; a phase modulating element provided in the second reference light path, the phase modulating element including a liquid crystal phase delay element to uniformly delay the phase in a traveling direction of the second reference light, and a biaxially-turning mirror to change the phases of two axis directions orthogonal to each other in a cross-sectional direction of the second reference light; and a control system configured to adjust the phase modulating element so that the phase difference between the diffracted light and the second reference light in a light receiving surface of the light receiving element is adjusted within a predetermined range, wherein the control system adjusts the phase modulating element based on a signal obtained from a corner portion of the light receiving element.