Charles Kuen Kao’s bold experiments proved data could be transmitted on light through glass fibres , laying the groundwork for today’s internet and a world transformed by connection.
In 1966, in a lab in Essex, electrical engineer Professor Sir Charles Kuen Kao (1933–2018) made a discovery that would transform modern communication.
Dubbed the “godfather of broadband” and “father of fibre optics,” Kao’s ideas laid the foundations for the development of the vast optical fibre networks that power today’s digital communications infrastructure and underpin the internet and world wide web.
Born in Shanghai in 1933, Kao moved with his family to Hong Kong in 1949, before completing his schooling and undergraduate degree in London. In 1957, while employed as a researcher at Standard Telecommunication Laboratories (STL) in Harlow, Kao registered as an external PhD student in Electrical Engineering at University of London under the supervision of UCL Professor Harold Barlow.
At STL, he started the experiments that would eventually demonstrate how glass fibres could be used to carry large amounts of information in pulses of light, many orders of magnitude more than was possible over copper or wirelessly.
At the time, many scientists believed that glass was unsuitable for transmitting light over long distances, as the signal faded after less than a metre. Kao and his colleagues demonstrated that the problem was not the glass itself but the impurities within it. If manufacturers could produce ultra-pure glass, light, and therefore information, could travel across cities or even continents with minimal signal loss. His ideas were initially met with scepticism, but within four years, the first fibre that was pure enough to give low losses was produced - and the internet was not far behind.
After two decades in England, Kao returned to Hong Kong to set up a new department of electronics at the Chinese University of Hong Kong, where he would later become Vice-Chancellor.
His groundbreaking contributions to fibre optics were recognised in 2009, when he was awarded the Nobel Prize for Physics. He was knighted a year later.
Diagnosed with Alzheimer’s disease in 2004, Kao and his wife, Lady Gwen Kao, established the Charles K Kao Foundation for Alzheimer’s Disease in 2010 to raise awareness of the condition and support for patients and carers.
I’m an engineer, so my real purpose is something that is useful… it is not the invention of something that is important. It is how we can utilize that, then, to improve life that is important.
Sources and explore further
- Polina Bayvel, Kao, Sir Charles Kuen [Gao Kun] (1933–2018), Oxford Dictionary of National Biography (March 2022)
- John Midwinter, Sir Charles Kuen Kao. 4 November 1933—23 September 2018, Royal Society (June 2021)
- Nobel Prize for Physics to UCL alumnus Professor Charles Kao, UCL News (December 2009)
