| 摘要 |
The present invention relates to an optical multi-layer information recording medium for recording information therein and/or retrieving information therefrom upon radiation of a convergent beam of light. The recording medium includes at least two pairs of recording layer and light-transmissive layer stacked one after another. A first recording layer proximal to a beam radiation side and a second recording layer distal from the beam radiation side are made from a material that satisfies a function including the following parameters; transmissivity and absorptance of the first recording layer, absorptance of the second recording layer, a numerical aperture on the first recording layer, a numerical aperture of the second recording layer, and transmissivity of between the first and second recording layers. Even if the numerical apertures change with spherical aberration compensation made to respective recording layers, a power density of a light spot does not change. Thus, recordation can be performed with consistent recording characteristics.
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