Bell Telephone Laboratories, Inc. List of Significant Innovations & Discoveries (1925-1983)


The first iteration of this list was compiled by Bell Labs alumnus A. Michael Noll in May 2012. 

(original list)

Original Notes:

  • Compiled by A. Michael Noll (with personal knowledge and an admitted bias toward speech research and computer graphics) and with sagacious comments from several Bell Telephone Laboratories colleagues.
  • Bell Telephone Laboratories, Inc. (BTL) was formed in 1925 and existed until the breakup of the Bell System on January 1, 1984. Only this period of nearly six decades is included here.
  • Innovations and discoveries were chosen to be significant new directions and not just incremental advances. However, a few “fascinating” ones, such as the “dunking bird,” have been included.
  • Tens of thousands of engineers, scientists, technicians, and others worked at Bell Telephone Laboratories, and all contributed in their own way to the overall accomplishments of the organization. Only a small few are listed here though.
  • On many of the larger development projects and systems, large engineering teams were involved, and accordingly individuals are not named.
Year Innovation or Discovery Innovators
1925 Electrical Sound Recording Joseph Maxfield & Harry Harrison
1925 Quality Control Theory W. A. Shewhart
1926 Thermal Noise John B. Johnson
1926 Antenna Arrays R. M. Foster
1926 Permendur Magnetic Alloy G. W. Elmen
1927 Negative Feedback Amplification Harold Black
1927 Television Transmission Herbert E. Ives
1927 Quartz Electronic Clock Warren Marrison
1927 Transatlantic Telephone Service Many contributors
1927 Wave Nature of the Electron Clinton J. Davisson & Lester. H. Germer
1927 Wearable Electronic Hearing Aid Harvey Fletcher
1927 Telephone Trunking Traffic Analysis Edward C. Molina
1928 Sampling Theorem Harry Nyquist
1929 Artificial Larynx Robert R. Riesz
1929 Broadband Coaxial Cable Lloyd Espenschied & Herbert A. Apfel
1929 Ship-to-Shore Radio System Many contributors
1929 Frequency Interleaving of TV Signal Frank Gray & John R. Hefele
1930 Moving-Coil Microphone E. C. Wente & A. L. Thuras
1930 Negative Impedance Repeater George Crisson
1931 Radio Astronomy Karl Jansky
1931 Rhombic Antenna Harald T. Friis & E. Bruce
1931 TWX Exchange Teletypewriter Svc Many contributors
1931 Stereophonic Recording on Film Harvey Fletcher
1931-32 Stereophonic Sound Rec. (45°) Harvey Fletcher, Arthur C. Keller
1932 Stability Criteria Diagrams Harry Nyquist
1932 Waveguide Experiments &Theory G. Southworth, A. King, A. E. Bowen
1933 Equal-Loudness Contours Harvey Fletcher & Wilden A. Munson
1933 Vitamin B1 Isolation Process Robert R. Williams
1933 Stereophonic Sound Transmission Harvey Fletcher
1934 Raster Scan TV System Pierre Mertz & Frank Gray
1936 Stereophonc Phonograph Record Arthur C. Keller & Irad S. Rafuse
1936 Vocoder Speech Synthesis Homer Dudley
1936 Reed Switch Walter B. Elwood
1936 High-Efficiency AM-Transmit. Amp. William H. Doherty
1937 Boolean Logic Relay Computer George Robert Stibitz & S. B. Williams
1937 Velocity Modulation Diode Frederick B. Llewellyn
1937 Isograph Analog Comp.for Poly. 0s R. L. Dietzold
1937-38 Voder Speech Synthesizer Homer Dudley
1938 Crossbar Switching System Many contributors
1938 Insertion Parameter Filter Design Sidney Darlington
1938 Phase-Gain Stability Criteria Hendrik W. Bode
1939 Complex Number Calculator George Robert Stibitz & S. B. Williams
1939 P-N Junction Russell Shoemaker Ohl
1939 Smith Chart for Transmission Lines Phillip H. Smith
1940 Pierce Electron Gun John R. Pierce
1940s Thermistor Materials G. L. Pearson, J. A. Becker & C. B. Green
1940 Reflex Klystron John R. Pierce & W. G. Shepherd
1940 Photovoltaic P-N Junction Russell Shoemaker Ohl
1941 Sound Spectrograph W. Koenig, H. K. Dunn & L. Y. Lacy
1941 Vocoder Speech Secrecy System R. K. Potter & R. C. Mathes
1942 Acoustic Homing Torpedo Many contributors
1942 Horn-Reflector Antenna Harald T. Friis amp; Alfred C. Beck
1943 Echo-Ranging Sonar Many contributors
1943 Microgel Synthetic Rubber William O. Baker & C. S. Fuller
1943 Computer-Contr. M5 Gun Director Many contributors
1944 Close-Spaced Triode (Model 416) Jack A. Morton
1944 Math.Treatment of Noise Theory Stephen O. Rice
1940s Microwave Radio Prop. Studies A. B. Crawford & collaborators
1945 Pulse Code Modulation Paper J. Pierce, C. Shannon & B. Oliver
1945 Nike Anti-Aircraft Missile Project Many contributors
1945 “Dunking Brid” Amusement Dev. Miles V. Sullivan
1945 Travelling-Wave-Tube Analysis John R. Pierce
1946 L1 Coaxial Cable System Many contributors
1946 Junction Solar Cell Patent Russell Shoemaker Ohl
1947 The Bit John W. Tukey
1947 Point-Contact Transistor John Bardeen & Walter H. Brattain
1947 Cellular Wireless Concept Donald H. Ring & W. Rae Young
1947 Helix Travelling Wave Tube John R. Pierce & L. M. Field
1947 Chirp Radar Sidney Darlington
1947 TDX Microwave Radio System Harald T. Friis & G. N. Thayer
1948 Information Theory Claude Shannon
1948 Error Correcting Codes Richard W. Hamming
1948 Bipolar Junction Transistor William Shockley
1949 Time Assignment Speech Interp. Carl B. H. Feldman
1949 Semicond.Particle Detectors Kenneth G. Mckay
1949 Gas Discharge Noise Tube W. W. Mumford
1950 TD Transcon. M-wave Rad. Sys. Many contributors
1950 Spat. Harm. Trav. Wv. Tube Amp. Sidney Millman
1950 Differential PCM of TV Signals C. C. Cutler, C. W. Harrison & B. M. Oliver
1950 Model of Basilar Membrane L. C. Peterson & Bruce P. Bogert
1950 High-Quality Synth,Qtz Growth A. Walker, G. Kohman, E. Buehler & R. Laudise
1950 Trans. Line Model of Vocal Tract H. K. Dunn
1951 Zone Refining William G. Pfann
1951 Direct Distance Dialing Many contributors
1951 Polymer Carbon W. O. Baker & F. H. Winslow
1951 Epitaxial Deposition Gordon Teal & Howard Christensen
1951 Stochastic Service Arrival Traffic J. Riordan
1952 Ion Implantation R. S. Ohl & William S. Shockley
1953 Photo-Transistor J. N. Shive
1953 Reflected Binary Code Frank Gray
1953 Avalanche Photodiode Physics Kenneth G. McKay & K. B. McAfee
1954 Photovoltaic Solar Cell D. Chapin, C. Souther Fuller & G. Pearson
1954 Formant Vocoder Eric S. Weibel
1954 Coaxial Magnetron Joseph Feinstein
1955 Lin.Floating-Dec. Prog.Langs. V. M. Wolontis & Richard W. Hamming
1955 Directive Antenna Arrays E. N. Gilbert & S. P. Morgan
1955 Diffused Emit. & Base Si Trans Morris Tanenbaum and D. E. Thomas
1955 Oxide Masking of Silicon Wafers Carl J. Frosh & Lincoln Derrick
1955 Pyrolytic C (Ablative HeatShield) F. H. Winslow & William O. Baker
1956 Polyethelene Cable Sheathing W. Lincoln Hawkins
1956 P-I-N Photodiode Theory W. T. Read, Jr.
1956 TAT-1 Many contributors
1957 Supermendur Magnetic Alloy H. L. B. Bould & D. H. Wenny
1957 Rare Earth Permanent Magnets J. H. Wernick & E. A. Nesbitt
1957 Minimal Tree Algorithm Robert C. Prim
1957 Computer Music Max V. Mathews
1957 Info. Rate of Human Channel John R. Pierce & John E. Karlin
1958 Bell 101 Dataset Modem Many contributors
1958 Laser Arthur L. Schawlow & Charles W. Townes
1958 Voice Excited Vocoder Manfred R. Schroeder
1958 Theory of Random Systems Philip Warren Anderson
1958 KNa Niobate Ceramic Del. Ln. L. Egerton & S. S. Flaschen
1958 Synthtic Quartz Crystal Growth Robert A. Laudise & Albert Ballman
1958 A/D Conversion Syst. for Audio E. David, Jr., M. Mathews & H. McDonald
1959 Macro-Instruction Programming M. Douglas McIlroy & Douglas E. Eastwood
1959 Nike Zeus Anti-Ballistic Missile Many contributors
1960 BLODI Block Diagr. Compiler John Kelly, Vic Vyssotsky & Carol Lochbaum
1960 Echo Communications Satellite John R. Pierce & team
1960 Order-of-Arrival Service Model Vaclav E. Benes
1960 MOS Transistor John Atalla & Dawon Kahng
1960 High Mag. Field Superconduc. J. Kunzler, F. Hsu, E. Buehler & J. Wernick
1960 Silicon Epitaxy Henry C. Theuerer
1960 Helium-Neon Gas Laser A. Javan, W. R. Bennet & D. R. Herriott
1960 Space Saver Rotary Dial Charles F. Matke
1960 Superconduc. Nb-Sn Magnet John Eugene Kunzler
1961 T1 Digital Carrier Introduced Many contributors
1961 Theory of Optical Resonators A. G. Fox & T. Li
1962 Cepstrum Pitch Detection Manfred R. Schroeder & A. Michael Noll
1962 Telstar Active Satellite Launch John R. Pierce & Eugene O’Neil’s team
1962 Electret Microphone Gerhard Sessler & James E. West
1962 Adaptive Echo Canceller J. Kelly, B. Logan, M. Sondhi & A. Presti
1962 Electronic Artificial Larynx H. L. Barney, F. E. Haworth & H. K. Dunn
1962 Basilar-Membrane Displace. James L. Flanagan
1962 Vocal-Tract Speech Synthesis John L. Kelly, Jr. & Carol Lochbaum
1962 Digital Computer Art A. Michael Noll
1962 Grating-Type Delay Line R. S. Duncan & Marsena R. Parker
1962 Red Helium-Neon Laser Alan White & J. Dane Rigden
1962-68 Nonmetric Mutltid.Scaling R. Shepard, J. Kruskal & Newman Guttman
1963 Digital Filter Design James F. Kaiser & Roger M. Golden
1963 Touchtone Dialing Leo Schenker
1963 Chemiluminescence Edwin A. Chandross
1963 BEFLIX Kenneth C. Knowlton
1963 Thin-Film Delay Line Norman F. Foster
1963 ALPAK W. Stanley, B. A. Tague & J. P. Hyde
1960s Comp. Animation apps. Many contributors
1964 Detect “Big-Bang” Radiation Arno A. Penzias & Robert W. Wilson
1964 Adaptive Equalizer Modem Robert W. Lucky
1964 CO2 High-Power Laser C. Kumar N. Patel
1964 YAG Laser J. E. Geusic, H. M. Marcos & L. G. Van Uitert
1964 Argon Laser Retina Repair Eugene I. Gordon & Edward F. Labuda
1964 Van Allen belt detection W. Brown, L. Lanzerotti & L. Medford
1964 MULTICS Time-Share Comp. Many contributors
1960s Random-Dot & Self Stereo. Bela Julesz
1965 Stereoscopic Comp. Anim. A. Michael Noll
1965 #1 Electronic Switching Sys. Many contributors
1965 FFT John Tukey & J. W. Cooley (IBM)
1965 Ded. Lab. Interactive Comp. Peter B. Denes
1965 Remote GDT William H. Ninke
1966 List-Processing Comp. Lang. Kenneth C. Knowlton
1966 Comp.-Aided Lib. Distribution W. Stanley Brown & Joseph F. Traub
1966 Silicon Gate R. E. Kerwin, D. L. Klein & J. C. Sarace
1967 Linear Predictive Coding Bishnu S. Atal & Manfred R. Schroeder
1967 Magn.Bubble Memory Devs A. H. Bobeck, H. E. D. Scovil & P. Michaelis
1967 Ion Implantation Implem. Alfred U. Mac Rae & Walter L. Brown
1968 Interactive 3D Input & Displ. A. Michael Noll
1968 Speech Synthesis by Rule Cecil H. Coker
1968 Heterostructure Semic.Laser I. Hayashi & M. Panish
1968 Molecular Beam Epitaxy John R. Arthur & A. Y. Cho
1968 LED for Optical Fibers C. A. Burrus
1969 UNIX™ Operating System Many contributors
1969 Charge Coupled Device William Boyle & George E. Smith
1969 Virtual Circ. Switch. (Spider) Alexander G. Fraser
1969 Strip Hologram Michael C. King
1969 Scanned-Display Raster A. Michael Noll
1970 Cell. Wless. Handoff Syst. A. Joel, Jr., R. Frenkiel, & P. Porter
1970 Adaptive Delta Modulation N. S. Jayant
1970 Cyl. Pb-Acid Central-Off. Bat. D. Koontz, D. Feder, L. Babusci & H. Leur
1970 Tact. Force-Fdbk. Haptic Sys. A. Michael Noll
1970 Ind. Diff. Multidim. Scaling J. Douglas Carroll & J. J. Chang
1970 Graded-Index Optical Fiber Many contributors
1972 Lightwave Repeater J. E. Goell, P. K. Runge
1972 Data Ring John R. Pierce & Cecil H. Coker
1972 Thin-Film Magn.-Optic Swit. Many contributors
1973 Cellular Switching Plan Z.Fluhr & Eric Nussbaum
1973 Adaptive Quant. Diff. PCM James L. Flanagan, P. Cummiskey & N. S. Jayant
1973 C Programming Language Dennis M. Ritchie
1974 Electronic Blackboard O. Gabe Torok
1974 Transvers. Dig.Filter Des. Lawrence R. Rabiner
1974 Comput. Tomography Alg. L. A. Shepp & B. F. Logan
1974 Dig. Wire Ctr & Sm. Dig.Switch Hank McDonald, Joseph Condon, & H. Alles
1975 Single-Mode Laser T. P. Lee, C. A. Burrus, B. I. Miller & R. A. Logan
1976 No.4 ESS Dig. Switch. Sys. Many contributors
1976 Video-Teleconf. Svc Joseph J. Horzepa & team
1976 CCIS Many contributors
1977 Comm. Optical-Fiber Trans. Many contributors
1977 Belle Ded.Chess Computer Joseph H. Condon & Kenneth L. Thompson
1977 Thry.of Disor. States of Mat. Philip W. Anderson
1977 Hematofluorometer Many contributors
1978 L5E Coaxial Cable System Many contributors
1978 Tele. Modular Plug & Jack Charles L. Krumreich
1978 32-bit Microprocessor L.Thomas, B. Murphy & Alfred U. Mac Rae
1978 XDS H. G. Alles, C. Christensen, R. W. Lucky
1978 800 service Roy P. Weber
1979 Psychoacoustic Mask. Cod. M. Schroeder, Bishu S. Atal & Joseph L. Hall
1979 Single-Chip DSP Many contributors
1980 Heterojuction Phototrans. J.A. Copeland, J. C. Campbell
1980 Dyn. Non-Hier. Ntwk. Rout. Gerald R. Ash & Richard H. Cartwell
1981 AR6A SSB-SC M-wave Syst. Many contributors
1982 5ESS® Dig.Switch. Syst. Many contributors
1982 Fractional Quant. Hall Effect Horst Störmer, Daniel Tsui & Robert Laughlin
1983 Hidden Markov Chain SR B-H Juang, S. Levinson, L. Rabiner, & M. Sondhi
1983 Twin-Tub VLSI CMOS Louis C. Parrillo & Richard S. Payne
1983 Code-Excited LPC Manfred R. Schroeder & Bishnu S. Atal

Sources: Impact, M. D. Fagen (Editor), 1971; A History of Engineering & Science in the BellSystem – Communications Sciences (1925-1980), S. Millman (Editor), 1984; A History of Engineering & Science in the Bell System – Physical Sciences (1925-1980), S. Millman (Editor), 1983.