Consumer Electronics

ORGANIC COMPOUNDS

Organic dyes exist that absorb a great deal of light and have a high reflectance even when applied in thin layers. These thin layers of organic compounds seem to be a promising alternative to tellurium–selenium alloys. The memory effect is again obtained by melting the material locally with a laser to create small pits. The difference from the tellurium–selenium alloy is that these pits do not normally penetrate through to the substrate. The reflectance varies with the depth of the pit. The difference in reflection created by the pattern of pits is used when the information is being read. The melting process is irreversible, so the disc can only be written once.

It has been found that these organic compounds retain the information ...