How the fibre communications revolution began

A few Key dates:

1958-62 – Laser proposed and demonstrated

  • (HeNe, Ruby, GaAs semiconductor)

1959 – Standard Telecommunication Laboratories moves to Harlow

  • Moved from Enfield, North London, to Harlow New Town

1963 – July

  • Charles Kao moves from the Long Haul Microwave Waveguide project, onto the Optical Communication project. His Notes A and Notes B.
  • He was later joined by George Hockham.

1966 – January:  First Press Release from parent company STC

“….It should be noted that when these methods are perfected, it will be possible to transmit very large quantities of information (telephone, television, data, etc.) between say, the Americas and Europe, along a single undersea cable.”!

1966 – July: The Paper that started it all:

  • “Dielectric-fibre surface waveguide for optical frequencies”, by K.C.Kao & G.A.Hockham, Published in the Proceedings of the IEE, in July 1966.

(Draft first received by the IEE on 24th November 1965, then in revised form 15th February 1966)

  • Proposes optical fibre communication would be viable if fibre loss less than 20 dB/km could be achieved

1969 – Evidence that pure Silica blocks had loss less than 10 dB/km

  • Mervyn Jones and Charles Kao

1970 – Breakthrough in fibre loss:

  • Corning report fibre with loss less than 20 dB/km

1972 – Corning achieve 4 dB/km fibre

1973 – First Commercial fibre transmission system

  • STC/STL sells the world’s first Commercial fibre transmission system to the Dorset Police in the UK. Fibre system replaced the co-ax cable (from the radio mast) which had been destroyed by lightning.

1974 – Bell Labs develop MOCVD process for production of preform

  • (Modified Chemical Vapour Deposition)

1975 – STL Demonstration of 1 Gbit/s transmission over 1 km of Single-mode fibre

1975 – STL Lab demo of 8 Mb/s HDB3 transmission system

1977 – Hitchin-Stevenage 140 Mb/s system

  • STL/STC install the first repeated fibre transmission system 9 km between telephone exchanges in Hitchin & Stevenage in the UK.
  • It used a total of 6 regenerators, multimode fibre, GaAs semiconductor lasers.
  • Required development of robust fibre cable, fibre splicing, demountable optical connectors etc..

Light Line – Video of the Hitchin-Stevenage system

Details in Paper at NTC77 Los Angeles

1977-8 – Discovery of Modal Noise in Multimode fibre – Move to Single mode

1980 – Deep water cable trial in Loch Fyne, Scotland

  • Single mode and multimode fibre, 140 Mb/s regenerator

1985 – September: UK-Belgium. World’s first international undersea system

1988 – TAT8 – World’s first transoceanic undersea optical fibre system

  • TAT = TransAtlantic Telephone. TAT8 was the 8th transatlantic cable system, the first with optical fibre which gave a huge increase in capacity between the UK and the USA.

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2016: Half a Century of Optical Fibre Communications

2016 was the 50th anniversary of the publication that started it all.

Optical Fibre has transformed our world yet is now almost completely ignored.

The reasons?:

  • It is largely hidden (beneath our streets and oceans).
  • No surviving commercial organisation has an interest in promoting the STL history.
  • Few remember just how poor global communications used to be.

Useful Links

For anyone who enjoyed STL

STL Quarter Century Club

For the full story of optical communication see

"City of Light - The Story of Fiber Optics" by Jeff Hecht

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