Optical memory comprising a tellurium cpd. - with a eutectic compsn. on substrate

摘要

Optical memory is formed from a layer of TeX (where X is Gp.III, IV or V element), the compsn. being close to the eutectic. The compsn. is doped with another element. The memory contains seed crystals for increasing its rapidity and/or optical contrast. Specifically seed crystals are of C, a metal esp. Te with the C axis arranged in the plane of the layer, and are 100 angstroms dia. The optical contrast is esp. increased by either forming an electrolytic deposit of a reflecting layer on the crystallised parts, electrolytically etching them, when the substrate is highly reflecting, or chemical dissolution of amorphous parts when the substrate is not highly reflecting.