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The media for CD-RW has the same layers as CD-R media. The reflective layer is, however, a silver-indium-antimony-tellurium alloy with a polycrystalline structure and reflective properties in its original state. When writing the laser beam uses its maximum power (8-14 mW) [6] to heat the material to 500–700 °C causing material liquefaction.
Retail recordable/writable optical media contain dyes in/on the optical media to record data, whereas factory-manufactured optical media use physical "pits" created by plastic molds/casts. As a result, data storage on retail optical media does not have the life-span of factory-manufactured optical media.
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.
For rewritable CD-RW, DVD-RW, DVD+RW, DVD-RAM, or BD-RE media, the laser is used to melt a crystalline metal alloy in the recording layer of the disc. Depending on the amount of power applied, the substance may be allowed to melt back (change the phase back) into crystalline form or left in an amorphous form, enabling marks of varying ...
As of 2021, multiple consumer-oriented, optical-disk media formats are or were available: Compact Disc ("CD"): digital audio disc CD-R: write once read many (WORM) CD; CD-RW: rewriteable CD; DVD: digital video disc DVD-R: WORM DVD defined by the DVD Forum; DVD-RW: rewritable DVD defined by DVD Forum; DVD+R: WORM DVD defined by the DVD+RW Alliance
To burn an optical disc, one usually first creates an optical disc image with a full file system, of a type designed for the optical disc, in temporary storage such as a file in another file system on a disk drive. One may test the image on target devices using rewriteable media such as CD-RW, DVD±RW and BD-RE.
CD-R, DVD-R, and DVD+R discs receive the dye layer after pressing but before metallization. CD-RW, DVD-RW and DVD+RW receive a metal alloy layer sandwiched between 2 dielectric layers. HD-DVD is made in the same way as DVD. In recordable and rewritable media, most of the stamper is composed of grooves, not pits and lands.
The history of optical recording can be divided into a few number of distinct major contributions. The pioneers of optical recording worked mostly independently, and their solutions to the many technical challenges have very distinctive features, such as reflective disc (Compaan and Kramer) transparent disc (Gregg) floppy disc (Russell)