| 摘要 |
An optical disk that has a structure wherein concentric or spiral guide grooves are made in a substrate and emboss-like pits are made between these guide grooves. The depth of the pits is such that a push-pull signal by the pits has an opposite polarity to that of a push-pull signal by the guide grooves. For example, the depth Dp of the pits, the width Wp of the pits and the depth Dg and the width Wg of the grooves are in the ranges expressed by 0.32 lambda /n</=Dp</=0.51 lambda /n, 0.27t</=Wp</=0.36t, 0.0875 lambda /n</=Dg</=0.1625 lambda /n, and 0.27t</=Wg</=0.36t, where lambda is the wavelength of the reproducing laser beam, n is the refractive index of the substrate, and t is the pitch of the tracks.
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