Compact Discs (CDs), Digital Versatile Discs (DVDs), and the like have leaded the market of optical recording media hitherto. However, a further increase in capacity of optical recording media has been demanded with distribution of high-definition televisions and a rapid increase in data handled by Personal Computers (PCs) in recent years. In order to respond to such a demand, high-capacity optical recording media compatible with blur laser, such as a Blu-ray Disc (BD) (registered trademark) have appeared, and a market of new high-capacity optical recording media has been launched.
A technique of providing multiple recording layers in order to further increase recording capacity in high-density optical recording media such as a DVD and a BD has widely been employed. Particularly, development of a multilayered optical recording medium provided with three or more recording layers has been advanced in recent years.
However, a signal property deteriorates due to interlayer stray light if multiple recording layers are provided. If three or more recording layers are provided in particular, stray light from parts other than a recording layer from which an information signal is intended to be read increases, and therefore, the signal property particularly significantly deteriorates.
For this reason, a technique of effectively suppressing an influence of the stray light and enhancing the signal property has been examined for the multilayered optical recording medium in the related art. PTLs 1 and 2 disclose techniques of removing an influence of multiple reflection caused by the stray light by setting the thickness of a spacer between information recording layers so as to satisfy a predetermined relationship.