Bell Telephone Laboratories, Inc. List of Significant Innovations & Discoveries (1925-1983)
From ETHW
The first iteration of this list was compiled by Bell Labs alumnus A. Michael Noll in May 2012.
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.
