Editing Optical disc (section)

== History ==
{{Main|History of optical storage media}}
[[Image:Lichttonorgelversuchsscheibe.jpg|thumb|220px|An earlier analog optical disc recorded in 1935 for {{interlanguage link|Lichttonorgel|de}} (sampling organ)]]{{multiple image|total_width=230px
| image1   = Lichtorgel.jpg
| image2   = Lichtscheiben.jpg
| footer   = Lichttonorgel & optical disc system
}}
{{Original research|date=July 2009}} <!-- those "generations" are very dubious and can probably not be found in any other reference work -->

The first recorded historical use of an optical disc was in 1884 when [[Alexander Graham Bell]], [[Chichester Bell]] and [[Charles Sumner Tainter]] recorded sound on a glass disc using a beam of light.<ref>{{cite web|url=http://newsdesk.si.edu/releases/playback-130-year-old-sounds-revealed|title=Playback: 130-Year-Old Sounds Revealed - Newsdesk|website=newsdesk.si.edu|access-date=3 May 2018|url-status=live|archive-url=https://web.archive.org/web/20170930085522/http://newsdesk.si.edu/releases/playback-130-year-old-sounds-revealed|archive-date=30 September 2017}}</ref>

Optophonie is a very early (1931) example of a recording device using light for both recording and playing back sound signals on a transparent photograph.<ref>{{Cite web|url=https://www.radiomuseum.org/forumdata/users/5100/Funkschau_4Jg_0131_1v1_v20.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.radiomuseum.org/forumdata/users/5100/Funkschau_4Jg_0131_1v1_v20.pdf |archive-date=2022-10-09 |url-status=live|title=Das Photo als Schalplatte|language=de|access-date=2020-07-02}}</ref>

An early analogue optical disc system existed in 1935, used on Welte's {{interlanguage link|Lichttonorgel|de}} sampling organ.<ref name=BushKassel2004p164>{{cite book |chapter=Electronic Organ |chapter-url=https://books.google.com/books?id=pmRuBwAAQBAJ&dq=Lichttonorgel%20sample&pg=PA164 |editor-first1=Douglas |editor-last1=Bush |editor-first2=Richard |editor-last2=Kassel |date=2004 |title=The Organ: An Encyclopedia |publisher=Taylor & Francis |isbn=978-1-135-94796-5 |page=164 |quote=In most recent instruments the itmbres have been “samples” (digitally recorded) from existing pipe organs, or resynthesized from samples. (This technology was anticipated by electromechanical oscillators during the 1930s, in what can retrospectively be described as “analog sampling”; examples included the photoelectric LichttonOrgel and the electrostatic Compton Electrone, both of which featured waveforms derived from well-known pipe organs.) |access-date=2023-03-21 |archive-date=2023-06-05 |archive-url=https://web.archive.org/web/20230605104243/https://books.google.com/books?id=pmRuBwAAQBAJ&dq=Lichttonorgel%20sample&pg=PA164 |url-status=live }}</ref>

An early analog optical disc used for video recording was invented by [[David Paul Gregg]] in 1958<ref>{{cite book |first=T.D. |last=Milster |chapter=Optical data storage |title=The Optics Encyclopedia: Basic Foundations and Practical Applications |publisher=Wiley |volume=3 [M–O] |date=2004 |isbn=978-3-527-40320-2 |pages= |oclc=314463541}}</ref> and patented in the US in 1961 and 1969. This form of optical disc was a very early form of the DVD <!--the DVD was developed from Greggs version rather than the earlier optical discs -->({{US Patent|3,430,966}}). It is of special interest that {{US Patent|4,893,297}}, filed 1989, issued 1990, generated [[royalty income]] for Pioneer Corporation's DVA until 2007 —then encompassing the CD, [[DVD]], and Blu-ray systems. In the early 1960s, the Music Corporation of America bought Gregg's patents and his company, Gauss Electrophysics.

American inventor [[James Russell (inventor)|James T. Russell]] has been credited with inventing the first system to record a digital signal on an optical transparent foil that is lit from behind by a high-power halogen lamp. Russell's patent application was first filed in 1966 and he was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents (then held by a Canadian company, Optical Recording Corp.) in the 1980s.<ref>{{cite news|last=Dudley|first=Brier|date=2004-11-29|title=Scientist's invention was let go for a song|newspaper=[[The Seattle Times]]|url=https://archive.seattletimes.com/archive/?date=20041129&slug=cdman29|url-status=live|access-date=2014-07-24|archive-url=https://web.archive.org/web/20140810225444/http://seattletimes.com/html/businesstechnology/2002103322_cdman29.html|archive-date=2014-08-10}}</ref><ref>{{cite press release |date=2000 |publisher=Reed College public affairs office |title=Inventor and Physicist James Russell '53 Will Receive Vollum Award at Reed's Convocation |access-date=2014-07-24 |url=http://reed.edu/news_center/press_releases/2000-2001/288.html |url-status=live |archive-url=https://web.archive.org/web/20131009170700/http://www.reed.edu/news_center/press_releases/2000-2001/288.html |archive-date=2013-10-09 }}</ref><ref>{{cite web|url=http://web.mit.edu/invent/iow/russell.html |title=Inventor of the Week - James T. Russell - The Compact Disc |date=December 1999 |publisher=[[MIT]] |url-status=dead |archive-url=https://web.archive.org/web/20030417162935/http://web.mit.edu/invent/iow/russell.html |archive-date=April 17, 2003 }}</ref>

Both Gregg's and Russell's disc are floppy media read in transparent mode, which imposes serious drawbacks, after this were developed four generations of optical drive that includes Laserdisc (1969), WORM (1979), Compact Discs (1984), DVD (1995), Blu-ray (2005), HD-DVD (2006), more formats are currently under development.

===First-generation===
From the start optical discs were used to store broadcast-quality analog video, and later digital media such as music or computer software. The [[LaserDisc]] format stored [[analog video]] signals for the distribution of [[home video]], but commercially lost to the [[VHS]] [[Videocassette#Cassette formats|videocassette]] format, due mainly to its high cost and non-re-recordability; other first-generation disc formats were designed only to store digital data and were not initially capable of use as a [[digital video]] medium.

Most first-generation disc devices had an infrared laser reading head. The minimum size of the laser spot is proportional to the [[wavelength]] of the laser, so wavelength is a limiting factor upon the amount of information that can be stored in a given physical area on the disc. The infrared range is beyond the long-wavelength end of the visible light spectrum, so it supports less density than shorter-wavelength visible light. One example of high-density data storage capacity, achieved with an infrared laser, is 700&nbsp;MB of net user data for a 12&nbsp;cm compact disc.

Other factors that affect data storage density include: the existence of multiple layers of data on the disc, the method of rotation ([[Constant linear velocity]] (CLV), [[Constant angular velocity]] (CAV), or zoned-CAV), the composition of lands and pits, and how much margin is unused is at the center and the edge of the disc.

Types of Optical Discs:
* [[Compact disc]] (CD) and derivatives
** [[Compact Disc Digital Audio|Audio CD]]
** [[Video CD]] (VCD)
** [[Super Video CD]]
** [[CD Video]]
** [[CD-Interactive]]
* [[LaserDisc]]
* [[GD-ROM]]
* [[Phase-change Dual]]
* [[Double Density Compact Disc]] (DDCD)
* [[Magneto-optical disc]]
* [[MiniDisc]] (MD)
** [[MD Data]]
* [[Write Once Read Many]] (WORM)

====Laserdisc====
In the [[Netherlands]] in 1969, [[Philips]] Research [[physicist]], Pieter Kramer invented an optical [[videodisc]] in reflective mode with a protective layer read by a focused [[laser]] beam {{US Patent|5,068,846}}, filed 1972, issued 1991. Kramer's physical format is used in all optical discs. 

In 1975, Philips and MCA began to work together, and in 1978, commercially much too late, they presented their long-awaited [[Laserdisc]] in [[Atlanta]]. MCA delivered the discs and Philips the players. However, the presentation was a commercial failure, and the cooperation ended.

In Japan and the U.S., [[Pioneer Corporation|Pioneer]] succeeded with the Laserdisc until the advent of the DVD. In 1979, Philips and [[Sony]], in consortium, successfully developed the [[audio compact disc]].

====WORM drive====

In 1979, Exxon STAR Systems in Pasadena, CA built a computer controlled WORM drive that utilized thin film coatings of Tellurium and Selenium on a 12" diameter glass disk. The recording system utilized blue light at 457&nbsp;nm to record and red light at 632.8&nbsp;nm to read. STAR Systems was bought by Storage Technology Corporation (STC) in 1981 and moved to Boulder, CO. Development of the WORM technology was continued using 14" diameter aluminum substrates. Beta testing of the disk drives, originally labeled the Laser Storage Drive 2000 (LSD-2000), was only moderately successful. Many of the disks were shipped to RCA Laboratories (now David Sarnoff Research Center) to be used in the Library of Congress archiving efforts. The STC disks utilized a sealed cartridge with an optical window for protection {{US Patent|4,542,495}}.

====CD-ROM====

The [[CD-ROM]] format was developed by Sony and [[Philips]], introduced in 1984, as an extension of [[Compact Disc Digital Audio]] and adapted to hold any form of digital data. The same year, Sony demonstrated a [[LaserDisc]] data storage format, with a larger data capacity of 3.28&nbsp;GB.<ref>[https://www.youtube.com/watch?v=rbh1XP4kCT4 Japanese PCs (1984)] {{Webarchive|url=https://web.archive.org/web/20170707091011/https://www.youtube.com/watch?v=rbh1XP4kCT4 |date=2017-07-07 }} (14:24), ''[[Computer Chronicles]]''</ref>

In the late 1980s and early 1990s, Optex, Inc. of Rockville, MD, built an erasable optical digital video disc system {{US Patent|5,113,387}} using Electron Trapping Optical Media (ETOM){{US Patent|5,128,849}}. Although this technology was written up in Video Pro Magazine's December 1994 issue promising "the death of the tape", it was never marketed.

Magnetic disks found limited applications in storing the data in large amount. So, there was the need of finding some more data storing techniques. As a result, it was found that by using optical means large data storing devices can be made that in turn gave rise to the optical discs. The very first application of this kind was the compact disc (CD), which was used in audio systems.

Sony and Philips developed the first generation of the CDs in the mid-1980s with the complete specifications for these devices. With the help of this kind of technology the possibility of representing the analog signal into digital signal was exploited to a great level. For this purpose, the 16-bit samples of the analog signal were taken at the rate of [[44,100 Hz|44,100 samples per second]]. This sample rate was based on the [[Nyquist rate]] of 40,000 samples per second required to capture the audible frequency range to 20&nbsp;kHz without aliasing, with an additional tolerance to allow the use of less-than-perfect analog audio pre-filters to remove any higher frequencies.<ref>Hass, J. ''Introduction to Computer Music'', Indiana University CECM (retrieved 8 October 2014), Volume One, Chapter Five: Digital Audio.{{cite web|title=Chapter Five: Principles of Digital Audio|url=http://www.indiana.edu/~emusic/etext/digital_audio/chapter5_rate.shtml|url-status=dead|archive-url=https://web.archive.org/web/20140608134439/http://www.indiana.edu/%7Eemusic/etext/digital_audio/chapter5_rate.shtml|archive-date=2014-06-08|access-date=2014-10-08}}</ref> The first version of the standard allowed up to 74 minutes of music or 650&nbsp;MB of data storage.

===Second-generation===
Second-generation optical discs were for storing great amounts of data, including broadcast-quality digital video. Such discs usually are read with a visible-light laser (usually red); the shorter wavelength and greater [[numerical aperture]]<ref name="Crutchfield Advisor">[http://www.crutchfieldadvisor.com/S-UNO5yLxzuZf/learningcenter/home/hd_blu.html?page=2 Format War Update: Blu-ray Wins Over HD DVD] {{webarchive|url=https://web.archive.org/web/20080110072357/http://www.crutchfieldadvisor.com/S-UNO5yLxzuZf/learningcenter/home/hd_blu.html?page=2 |date=2008-01-10 }}. Crutchfieldadvisor.com. Retrieved on 2011-10-09.</ref> allow a narrower light beam, permitting smaller pits and lands in the disc. In the DVD format, this allows 4.7&nbsp;GB storage on a standard 12&nbsp;cm, single-sided, single-layer disc; alternatively, smaller media, such as the [[DataPlay]] format, can have capacity comparable to that of the larger, standard compact 12&nbsp;cm disc.<ref>{{cite web|title=Optical Carriers|url=http://webworld.unesco.org/safeguarding/en/pdf/txt_opti.pdf|url-status=dead|archive-url=https://web.archive.org/web/20151214233640/http://webworld.unesco.org/safeguarding/en/pdf/txt_opti.pdf|archive-date=2015-12-14|access-date=2013-11-27}}</ref>

* [[DVD]] and derivatives
** [[DVD-Audio]]
** [[DualDisc]]
** [[DIVX|Digital Video Express]] (DIVX)
** [[DVD-RAM]]
** [[DVD±R]]
* [[Nintendo optical discs#GameCube Game Disc|Nintendo GameCube Game Disc]] (miniDVD derivative)
* [[Nintendo optical discs#Wii Optical Disc|Wii Optical Disc]] (DVD derivative)
* [[Super Audio CD]] (SACD)
* [[Enhanced Versatile Disc]]
* [[DataPlay]]
* [[Hi-MD]]
* [[Universal Media Disc]] (UMD)
* [[Ultra Density Optical]]

====DVD-ROM====

In 1995, a consortium of manufacturers (Sony, Philips, [[Toshiba]], [[Panasonic]]) developed the second generation of the optical disc, the [[DVD]].<ref>{{cite thesis|last=Hawan Kim|first=Sung|title=June 2004|url=http://dspace.mit.edu/bitstream/handle/1721.1/17865/56611707.pdf|publisher=Massachusetts Institute of Technology|url-status=live|archive-url=https://web.archive.org/web/20131204001454/http://dspace.mit.edu/bitstream/handle/1721.1/17865/56611707.pdf|archive-date=2013-12-04|year=2004|type=Thesis}}</ref> The [[DVD]] disc appeared after the CD-ROM had become widespread in society.

===Third-generation===
Third-generation optical discs are used for distributing [[HDTV|high-definition video]] and videogames and support greater data storage capacities, accomplished with short-wavelength visible-light lasers and greater numerical apertures. Blu-ray Disc and HD DVD uses blue-violet lasers and focusing optics of greater aperture, for use with discs with smaller pits and lands, thereby greater data storage capacity per layer.<ref name="Crutchfield Advisor" />
In practice, the effective multimedia presentation capacity is improved with enhanced video [[data compression]] [[codec]]s such as [[H.264/MPEG-4 AVC]] and [[VC-1]].

* [[Blu-ray]] and derivatives (up to 400&nbsp;GB - experimental<ref>{{cite web|last=Ricker|first=Thomas|date=2008-07-07|title=Pioneer's Blu-ray disc hits 400GB across 16-layers|url=https://www.engadget.com/2008/07/07/pioneers-blu-ray-disc-hits-400gb/|url-status=live|archive-url=https://web.archive.org/web/20170824205025/https://www.engadget.com/2008/07/07/pioneers-blu-ray-disc-hits-400gb/|archive-date=2017-08-24|website=www.engadget.com}}</ref><ref>{{cite web | website = www.gizmag.com | url = http://www.gizmag.com/pioneer-develops-16-layer-400-gb-optical-disc/9598/ | title = Pioneer's 400 GB Blu-ray Disc | date = 8 July 2008 | url-status = live | archive-url = https://web.archive.org/web/20130925124548/http://www.gizmag.com/pioneer-develops-16-layer-400-gb-optical-disc/9598/ | archive-date = 2013-09-25 }}</ref>)
** [[Blu-ray Disc recordable|BD-R and BD-RE]]
** [[High Fidelity Pure Audio]]
** [[AVCHD]] and [[AVCREC]]
** BDXL and Blu-ray 3D
** [[Ultra HD Blu-ray|4K Blu-ray]] and 8K Blu-ray<ref>{{cite web|url=https://displaydaily.com/blu-ray-disc-association-settles-on-8k-format/|title=Blu-ray Disc Association Settles on 8K Format|first=Chris|last=Chinnock|date=January 22, 2018|access-date=August 24, 2023}}</ref>
* [[Nintendo optical discs#Wii U Optical Disc|Wii U Optical Disc]] (25 GB per layer)
* [[HD DVD]] (discontinued disc format, up to 51&nbsp;GB triple layer)
* [[China Blue High-definition Disc|CBHD]] (a derivative of the HD DVD format)
* [[HD VMD]]
* [[Professional Disc]]
Announced but not released:
* [[Digital Multilayer Disk]]
* [[Fluorescent Multilayer Disc]]
* [[Forward Versatile Disc]]

====Blu-ray and HD-DVD====

The third generation optical disc was developed in 2000–2006 and was introduced as Blu-ray Disc. First movies on Blu-ray Discs were released in June 2006.<ref>{{cite web|last=Drawbaugh|first=Ben|date=June 19, 2006|title=HD DVD and Blu-ray movies released on June 20th 2006|url=https://www.engadget.com/2006/06/19/hd-dvd-and-blu-ray-movies-released-on-june-20th-2006/|url-status=live|archive-url=https://web.archive.org/web/20180411111451/https://www.engadget.com/2006/06/19/hd-dvd-and-blu-ray-movies-released-on-june-20th-2006/|archive-date=2018-04-11|publisher=Engadget International Editions}}</ref> Blu-ray eventually prevailed in a [[high definition optical disc format war]] over a competing format, the [[HD DVD]]. A standard Blu-ray disc can hold about 25&nbsp;GB of data, a DVD about 4.7&nbsp;GB, and a CD about 700&nbsp;MB.

[[File:Comparison CD DVD HDDVD BD.svg|thumb|300px|Comparison of various optical storage media]]

===Fourth-generation===
The following formats go beyond the current third-generation discs and have the potential to hold more than one terabyte (1 [[Terabyte|TB]]) of data and at least some are meant for cold [[computer data storage|data storage]] in [[data centers]]:<ref>{{Cite web |title=Sony Everspan Optical Disc Data Archive System Ready For IoT |url=http://www.hughsnews.ca/sony-everspan-optical-disc-data-archive-system-ready-for-iot-0056191 |access-date=2023-03-02 |website=www.hughsnews.ca |archive-date=2023-06-05 |archive-url=https://web.archive.org/web/20230605104244/http://www.hughsnews.ca/sony-everspan-optical-disc-data-archive-system-ready-for-iot-0056191 |url-status=live }}</ref>{{dubious|date=May 2020}}
* [[Archival Disc]]
* [[Holographic Versatile Disc]]
Announced but not released:
* [[LS-R]]
* Protein-coated disc
* [[Stacked Volumetric Optical Disc]]
* 5D DVD
* [[3D optical data storage]] (not a single technology, examples are [[Hyper CD-ROM]] and [[Fluorescent Multilayer Disc]])

In 2004, development of the [[Holographic Versatile Disc]] (HVD) commenced, which promised the storage of several terabytes of data per disc. However, development stagnated towards the late 2000s due to lack of funding.

In 2006, it was reported that Japanese researchers developed ultraviolet ray lasers with a wavelength of 210 nanometers, which would enable a higher [[bit]] density than Blu-ray discs.<ref>{{Cite web |last=Kleiner |first=Kurt |date=17 May 2006 |title=Ultraviolet LED may boost disc capacity |url=https://www.newscientist.com/article/dn9183-ultraviolet-led-may-boost-disc-capacity/ |access-date=2022-04-18 |website=New Scientist |language=en-US |archive-date=2022-04-18 |archive-url=https://web.archive.org/web/20220418211948/https://www.newscientist.com/article/dn9183-ultraviolet-led-may-boost-disc-capacity/ |url-status=live }}</ref> As of 2022, no updates on that project have been reported.

===Overview of optical types===
{| class="wikitable sortable"
|-
! Name !! Capacity !! Experimental<ref group=Note>Prototypes and theoretical values.</ref> !! Years<ref group=Note>Years from (known) start of development till end of sales or development.</ref>

|-
| [[LaserDisc]] (LD) || N/A || || 1971–2007
|-
| [[Write Once Read Many Disk]] (WORM) || 0.2–6.0 GB || || 1979–1984
|-
| [[Compact disc]] (CD) || 0.7–0.9 GB || || 1982–present
|-
| Electron Trapping Optical Memory (ETOM) || 6.0–12.0 GB || || 1987–1996
|-
| [[MiniDisc]] (MD) || 0.14–1.0 GB || || 1989–2025
|-
| [[Magneto-optical drive|Magneto Optical Disc]] (MOD) || 0.1–16.7 GB || || 1990–present
|-
| [[DVD|Digital Versatile Disc]] (DVD) || 4.7–17 GB || || 1995–present
|-
| [[LIMDOW]] (Laser Intensity Modulation Direct OverWrite) || 2.6 GB||10 GB||1996–present
|-
| [[GD-ROM]] || 1.2 GB || || 1997–2006
|-
| [[Fluorescent Multilayer Disc]] || || 50–140 GB || 1998-2003
|-
| [[Versatile Multilayer Disc]] (VMD) || 5–20 GB || 100 GB || 1999-2010
|-
| [[Hyper CD-ROM]] || 1 PB || 100 EB ||1999–present
|-
| [[DataPlay]] || 500 MB || || 1999-2006
|-
| [[Ultra Density Optical]] (UDO) || 30–60 GB || || 2000–present
|-
| [[Forward Versatile Disc]] (FVD) || 5.4–15 GB || || 2005–2006<ref>{{cite web |author1=Computer Language Company |title=Definition: FVD |url=https://www.computerlanguage.com/results.php?definition=Forward+Versatile+Disc |access-date=11 October 2024 |ref=CLCFVD}}</ref>
|-
| [[Enhanced Versatile Disc]] (EVD) || DVD || || 2002-2004
|-
| [[HD DVD]] || 15–51 GB || 1 TB{{Citation_needed|reason=|date=December 2015}} || 2002-2008
|-
| [[Blu-ray Disc]] (BD) || 25 GB<br />50 GB || || 2002–present
|-
| [[BDXL]] || 100 GB, 128 GB || 1 TB || 2010–present
|-
| [[Professional Disc for Data]] (PDD) || 23 GB || || 2003-2006
|-
| [[Professional Disc]] || 23–128 GB || || 2003–present
|-
| [[Digital Multilayer Disk]] || || 22-32 GB || 2004–2007
|-
| [[Multiplexed Optical Data Storage]] (MODS-Disc) || || 250 GB–1 TB || 2004–present
|-
| [[Universal Media Disc]] (UMD) ||0.9–1.8 GB || || 2004–2014
|-
| [[Holographic Versatile Disc]] (HVD) || || 6.0 TB || 2004–2012
|-
| Protein-coated disc (PCD) || || 50 TB || 2005–2006
|-
| [[M-DISC]] || 4.7 GB (DVD format)<br />25 GB (Blu-ray format)<br />50 GB (Blu-ray format)<br /> 100 GB ([[Blu-ray#BDXL|BDXL]] format) <ref>{{cite web|url=http://www.mdisc.com/100gb|title=100 GB Disc - M-DISC|website=www.mdisc.com|access-date=3 May 2018|archive-url=https://web.archive.org/web/20151018064310/http://www.mdisc.com/100gb/|archive-date=18 October 2015|url-status=dead}}</ref> || || 2009–present
|-
| [[Archival Disc]] || 0.3-1 TB || || 2014–2024
|-
| [[Ultra HD Blu-ray]] || 50 GB<br />66 GB<br />100 GB<br />128 GB || || 2015–present
|-
|}
;Notes
<references group=Note/>