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A CD-RW (CD). Amorphous chalcogenide materials form the basis of re-writable CD and DVD solid-state memory technology. [3] Uses include infrared detectors, mouldable infrared optics such as lenses, and infrared optical fibers, with the main advantage being that these materials transmit across a wide range of the infrared electromagnetic spectrum.
Various forms of optical media, mostly disk form, competed with magnetic recording through most of the 1960s and 70s, but never became widely used. It was the introduction of semiconductor lasers that provided the technology needed to make optical storage more practical in both storage density and cost terms.
GeSbTe (germanium-antimony-tellurium or GST) is a phase-change material from the group of chalcogenide glasses used in rewritable optical discs and phase-change memory applications. Its recrystallization time is 20 nanoseconds, allowing bitrates of up to 35 Mbit/s to be written and direct overwrite capability up to 10 6 cycles. It is suitable ...
[citation needed] Chalcogenide is the same material used in re-writable optical media (such as CD-RW and DVD-RW). In those instances, the material's optical properties are manipulated, rather than its electrical resistivity, as chalcogenide's refractive index also changes with the state of the material.
In optical storage, three types of storage are usually recognized, and given customary abbreviations: read-only ("ROM"), Write once ("R") and read/writable ("RW", or for Blu-ray, "E" for "erasable"). Examples: CD-ROM represents the CD format, in its pre-recorded "read only" use; DVD+R represents a DVD "+" disc which can be written once only
Rewritable media is typically used in archive applications where the stability and longevity of optical media are important, but archive records change on a relatively frequent or discretionary basis. Rewritable media is typically used in archive environments where data needs to be deleted or media capacity re-used. True write once
Media technologies vary, for example, M-DISC media uses a rock-like layer to retain data for longer than conventional recordable media. While being read-only compatible with existing DVD and Blu-ray drives, M-DISC media can only be written to using a stronger laser specifically made for this purpose, which is built into fewer optical drive models.
DVD recordable and DVD rewritable are a collection of optical disc formats that can be written to by a DVD recorder and by computers using a DVD writer.The "recordable" discs are write-once read-many (WORM) media, where as "rewritable" discs are able to be erased and rewritten.