History of optical storage media

Although research into optical data storage has been ongoing for many decades, the first popular system was the Compact Disc, introduced in 1982, adapted to data storage (the CD-ROM format) with the 1985 Yellow Book, and re-adapted as the first mass market optical storage medium with CD-R and CD-RW in 1988. Compact Disc is still the "de facto" standard for audio recordings, although its place for other multimedia recordings and optical data storage has largely been superseded by DVD.

DVD (initially an acronym of "Digital Video Disc", then backronymed as "Digital Versatile Disc" and officially just "DVD") was the mass market successor to CD. [ [http://www.pcmag.com/encyclopedia_term/0,2542,t=backronym&i=56302,00.asp backronym Definition ] ] DVD was rolled out in 1996, again initially for video and audio. DVD recordable formats developed some time later: DVD-R in late 1997 and DVD+R in 2002. Although DVD was initially intended to prevent a format war in fact one did arise between these two formats. It was resolved with both surviving however: DVD-R predominating for stand-alone DVD recorders and players, and (for computers) most DVD devices being engineered as dual format, to be compatible with both. As of 2007 DVD is the "de facto" standard for pre-recorded movies, and popular storage of data beyond the capacity of CD.

With the development of high definition television, and the popularization of broadband and digital storage of movies, a further format development took place, again giving rise to two camps: HD DVD and Blu-ray Disc, based upon a switch from red to blue-violet laser and tighter engineering tolerances. As of 2007 both have significant releases in the pre-recorded movie sector, but they are still only commencing their roll-out for data storage and more general use, and have as yet made little impact on the global market for data storage. After suffering a number of significant losses to Blu-ray, Toshiba announced their withdrawal from HD DVD on February 19, 2008.

As of 2007, future development beyond HD DVD and Blu-ray Disc appear to be based upon one or more of the following technologies, all in varying stages of development:
* Holographic data storage.
* 3D optical data storage.
* Nearfield optics.
* Solid immersion optics (allowing an extremely high numerical aperture).
* Discs utilizing very short wavelengths such as UV or X-rays.
* Layer selection discs (LS-R).
* Multi-level technology.
* Complex pit shapes allowing multiple channels to be stored on one track.
* Wavelength multiplexing techniques.

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