Contrast Inversion for Optical Recording

摘要

A recordable medium includes an inscription layer and at least one contrast inverting layer. The inscription layer has at least a first sub-layer and a second sub-layer that combine upon application of a write power. The inscription layer has a reflectivity R 1 with respect to a read beam before application of the write power and a reflectivity R 2 after application of the write power, and R 1 <R 2 . The at least one contrast inverting layer does not combine with the first and second sub-layers of the inscription layer upon application of the write power. The at least one contrast inverting layer and the inscription layer together have a reflectivity R 3 before application of the write power and a reflectivity R 4 after application of the write power, and R 3 >R 4.