OPTICAL STORAGE MEDIUM COMPRISING A MULTILEVEL DATA LAYER

摘要

The optical storage medium comprises a substrate layer (2), a data layer(3), and a nonlinear layer (4) with a super-resolution structure disposed on the data layer (3), wherein pits and lands having a size above a diffraction limit of a pickup for reading of the data establish a first and a second level (L1, L2) of the data layer, and pits and lands having a size below the diffraction limit of the pickup are arranged on a further level (L3, L4) of the data layer (3). In a preferred embodiment, pits having a size below the diffraction limit are arranged on a third level (L3) and lands having a size below the diffraction limit are arranged on a fourth level (L4) of the data layer. The optical storage medium is in particular a read only optical disc comprising a phase-change material, for example AgInSbTe, for providing the super-resolution effect.