| 摘要 |
A holographic recording medium (101) includes a recording layer (101b) in which data are to be recorded as volume phase information of light by projecting a signal beam (102) and a reference beam (102) thereonto, a reflective surface (101f) disposed on the opposite side of the recording layer as viewed in the direction of signal beam and reference beam incidence on the holographic recording medium and formed with a convex pattern (103) or a concave pattern (701) having a trapezoidal cross-section, a minimum width (D1) of a convex surface of the convex pattern or a concave surface of the concave pattern being set equal to or larger than a beam spot diameter ( DIAMETER 1) of the signal beam or the reference beam at a diffraction limit thereof, thereby forming a spatial filter region. According to the thus constituted holographic recording medium, it is possible to easily remove noise light (102x) contained in a signal beam and a reference beam i.e. that fraction of light which is formed with spot diameter ( DIAMETER 2) larger than D1. <IMAGE>
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