How the fibre communications revolution began

Sir Charles Kuen Kao

Charles Kao experimenting with a single-mode optical fibre

Charles Kao experimenting with a prototype single-mode optical fibre made of glass, in the lab at STL

The Vision

A young Charles Kao became the driving force behind the idea of long distance communication using a single-mode optical fibre waveguide made of glass. The idea seemed impossible to most researchers at the time due to the poor optical characteristics of the best available glass material. He and George Hockham thoroughly investigated whether there were any fundamental limits and found none. The comprehensive results of this research were published in the paper which is now recognised as the very beginning of the optical fibre revolution. Charles then toured research labs around the world (e.g. USA. France, Japan) in an attempt to convince others of the idea, for he realised that it’s success would depend on the contributions of others.


Charles Kuen Kao was born in Shanghai on the 4th of November 1933. He is a Chinese-born Hong Kong, American and British electrical engineer and physicist who pioneered in the development and use of fibre optics in telecommunications. He holds multiple citizenship of Hong Kong, the United Kingdom and the United States.

His family moved to Hong Kong in 1948 where he completed his secondary education, then moved to England in 1952 to do his undergraduate studies in electrical engineering at Woolwich Polytechnic (now the University of Greenwich), obtaining his Bachelor of Science degree.

Charles Kao at STC Woolwich

A young Charles Kao as a member of Jeff Dawson’s group at STC Woolwich (circled)

He joined Standard Telephones and Cables at Woolwich, pursuing research into microwave communications using Long Haul Microwave Waveguides. In 1965 he received his PhD degree in electrical engineering  from University College London (under Professor Harold Barlow) as an external student while working at Standard Telecommunication Laboratories (STL) in Harlow, Essex, England, the research centre of Standard Telephones and Cables. It is there that Kao did his first ground-breaking work as an engineer and researcher working alongside George Hockham, initially under the supervision of Alec Reeves.

In 1963 he had joined the team of people who were exploring possible ways of achieving optical communication, and he made some diligent notes summarising the whole situation at the time, and identifying the team members and their areas of expertise. These notes now reside in The Nobel Prize museum in Oslo, but copies can be viewed here:

Young Charles Kao’s notes from 1963: Set A & Set B

Photo of Charles Kao during visit to STL in 20022009 Nobel Prize

In 2009 Charles was awarded the Nobel Prize in Physics. One half was awarded to Charles “for groundbreaking achievements concerning the transmission of light in fibers for optical communication”, the other half jointly to Willard S. Boyle and George E. Smith “for the invention of an imaging semiconductor circuit – the CCD sensor”. The Nobel Prize in Physics 2009

Charles’ Biography on the Nobel Prize website


On June 11th, 2010 Charles was awarded a knighthood in the British Queen’s Birthday Honours: The Knight Commander of the Most Excellent Order of the British Empire (KBE)

Other awards and medals
Autobiographical Memoir by Charles & Gwen Kao

A Time and Tide - A Memoir, biography by Charles Kao

A Time and Tide – A Memoir, by Charles Kao

Extensive details of his life are contained in his biography: A Time and A Tide – A Memoir – Charles K. Kao, with additional recent material added by Gwen Kao.

This is now available in eBook format

Alzheimer’s Disease

Sadly Charles was diagnosed with Alzheimer’s Disease in 2004 and his health has subsequently deteriorated. Gwen Kao cares for him and now runs The Charles K. Kao Foundation for Alzheimer’s Disease.

This charitable organization was founded in 2010 by Charles K. Kao and his wife, Gwen Kao. It is based in Hong Kong which is now their home. The Foundation aims to raise the public awareness of Alzheimer’s disease, educating the general public on brain healthcare strategies, enhancing care and support to Alzheimer’s patients, their families and caregivers. Words from Gwen Kao

Wikipedia entry for Charles K. Kao

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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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