Bell Telephone Laboratories (or sometimes AT&T Bell Laboratories), best known as Bell Labs, was originally the research and development arm of the United States Bell System. It was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to specialized coverings for telephone cables, including the famous discovery of the transistor.
In 1925, Walter Gifford, then president of AT&T, established Bell Telephone Laboratories Inc as a separate entity which took over work previously conducted by the research division of Western Electric's engineering department. Half of Bell Labs was owned by Western Electric, the other half being owned by AT&T.
Discoveries made at Bell Labs include:
- 1925: Facsimile (fax) transmission first demonstrated publicly
- 1927: Long-distance television transmission, of images of Herbert Hoover, from Washington to New York
- 1928: Thermal noise in a resistor is measured by J.B. Johnson; Harry Nyquist provides a theoretical analysis.
- 1920s: The one-time pad cipher invented by Gilbert Vernam and Joseph Mauborgne; Bell's Claude Shannon later proved that it was unbreakable
- 1933: Foundation of radio astronomy laid by Karl Jansky; in his work investigating the origins of static on long distance communications, he discovered that radio waves were being emitted from the centre of the galaxy
- 1933: Stereo signals transmitted live from Philadelphia to Washington D.C.
- 1937: The vocoder, the first electronic speech synthesizer, invented and demonstrated by Homer Dudley
- 1940: The photovoltaic cell developed by Russell Ohl
- 1947: The transistor is invented by John Bardeen, William Bradford Shockley, and Walter Houser Brattain, all of whom subsequently won the Nobel Prize in Physics in 1956
- 1948: "A Mathematical Theory of Communication", one of the founding works in information theory, published by Claude Shannon in the Bell System Technical Journal; it built in part on earlier work in the field by Bell researchers Harry Nyquist and Ralph Hartley
- 1949: First remote operation of a teleprinter, controlled in New Hampshire by a computer at Bell Labs in New York City
- 1956: TAT-1, the first transatlantic telephone cable laid between Scotland and Newfoundland
- 1957: MUSIC, one of the first computer programs to play electronic music, created by Max Mathews
- 1958: The laser is first described in a technical paper by Arthur Schawlow and Charles Townes
- 1962: Light-emitting diodes (LEDs) invented by Nick Holonyak
- 1964: Carbon dioxide laser invented by Kumar Patel
- 1966: Orthogonal frequency-division multiplexing (OFDM), a key technology in wireless services, developed and patented by R. W. Chang
- 1968: Molecular beam epitaxy developed by J.R. Arthur and A.Y. Cho; allows semiconductor chips and laser matrices to be created one atomic layer at a time
- 1969: UNIX operating system is created by Dennis Ritchie and Ken Thompson
- 1970: C programming language developed by Ritchie and Thompson
- 1971: A computerized switching system for telephone traffic, invented by Erna Schneider Hoover, receives one of the first software patents
- 1976: Fiber optics systems first tested in Georgia
- 1980: First single-chip 32-bit microprocessor, the BELLMAC-32A, is demonstrated; it goes into production in 1982
- 1980: TDMA and CDMA digital cellular telephone technology patented
- 1982: Fractional quantum Hall effect discovered by Horst Störmer and former Bell Labs researchers Robert B. Laughlin and Daniel C. Tsui; they won a Nobel Prize for it in 1998
- 1983: The C++ programming language is developed by Bjarne Stroustrup
- 1984: Karmarkar Linear Programming Algorithm developed by mathematician Narendra Karmarkar
- 1985: Laser cooling used to slow and manipulate atoms by Steven Chu and team
- 1980s: Plan 9 operating system is devloped as a replacement for Unix
- 1988: TAT-8 is the first fiber optic transatlantic cable
- 1990: WaveLAN is the first wireless local area network (LAN)
- 1991: 56K modem technology patented by Nuri Dagdeviren and team
- 1994: Quantum cascade laser invented by Federico Capasso, Claire Gmachl and team
- 1995: Wireless internet access first demonstrated
- 1996: SCALPEL electron lithography, which prints features atoms wide on microchips, invented by Lloyd Harriott and team
- 1996: The Inferno operating system, an update of Plan 9, is created by Dennis Ritchie and team using the new concurrent Limbo programming language
- 1997: Smallest practical transistor created, 60 nanometers or 182 atoms wide
- 1998: First optical router
- 1998: First combination of voice and data traffic on an Internet Protocol (IP) network
- 2000: DNA machine prototypes developed
- 2000: Progressive geometry compression algorithm makes widespread 3-D communication practical
- 2000: First electrically powered organic laser
- 2000: Large-scale map of cosmic dark matter provided
- 2000: F-15, an organic material that makes plastic transistors possible, invented
After the 1984 divestiture agreement with the government that broke up AT&T, Bellcore was split off from Bell Labs to provide the same R&D functions for the newly created local exchange carriers. AT&T was also limited to using the Bell trademark in association with Bell Labs.
In 1996 AT&T spun off Bell Labs, along with most of its equipment-manufacturing business, into a new company named Lucent Technologies. AT&T retained a smaller number of researchers to form AT&T Laboratories.
In 2002 Jan Hendrik Schön, a German physicist, was fired from Bell Labs after his work was found to contain fraudulent data; it was the first case of fraud in the lab's history. Over a dozen of Schön's papers were found to contain fictional or altered data, including a paper on molecular-scale transistors that was portrayed as a breakthrough.
At its height, Bell Labs had research and development facilities all over the USA,though mostly concentrated in the majority of areas in New Jersey; but before the telecomm bust of 2000, the Naperville-Lisle location had the single largest concentration of people (about 11,000). Among the locations were Westminster in Colorado, Crawford Hill, Freehold, Holmdel, Lincroft, Long Branch, Middletown, Murray Hill, Piscataway, Red Bank, Whippany, Naperville, Lisle,Columbus in Ohio, Allentown and Breinigsville.
Bell Labs is currently located in Murray Hill, New Jersey. Within the past five years, many of the former Bell Labs locations have been scaled back or shutdown entirely.
The work done by Bell Labs was broadly divided into three categories: research, systems engineering, and development.
Systems engineering concerned itself with conceiving the highly complex systems that make up the telecommunication networks.
Calculators built by Bell Labs
- Model I - Complex Number Calculator, completed January 1940, for doing calculations of complex numbers
- Model II - Relay Calculator or Relay Interpolator, September 1943, for aiming anti-aircraft guns by interpolating from positions
- Model III - Ballistic Computer, June 1944, for calculations of ballistic trajectories
- Model IV - Bell Laboratories Relay Calculator, March 1945, a second Ballistic Computer
- Model V - Bell Laboratories General Purpose Relay Calculator, two were built: July 1946 and February 1947. These were general-purpose programmable computers using electromechanical relays.
- Model VI - November 1950, an enhanced Model V.
- Bell Labs
- Timeline of discoveries
- Bell Labs' Murray Hill anechoic chamber
- Google maps satellite view of the Murray Hill Facility