In the 1960s, Kao created various methods to combine glass fibres with lasers in order to transmit digital data, which laid the groundwork for the evolution of the Internet and the eventual creation of the World Wide Web.

[5] Known as the "godfather of broadband",[6] the "father of fibre optics",[7][8][9][10][11] and the "father of fibre optic communications",[12] he continued his work in Hong Kong at the Chinese University of Hong Kong, and in the United States at ITT (the parent corporation for STC) and Yale University.

Kao was awarded the Nobel Prize in Physics for "groundbreaking achievements concerning the transmission of light in fibres for optical communication".

[17][16]: 41  He also studied English and French at the Shanghai World School (上海世界學校)[18] that was founded by a number of progressive Chinese educators, including Cai Yuanpei.

[16]: 1 [20] Kao's family lived in Lau Sin Street, at the edge of the North Point, a neighbourhood of Shanghai immigrants.

However, at the time electrical engineering wasn't a programme available at the University of Hong Kong, the territory's then only teritary education institute.

[25][16]: 1 [26][24] He then pursued research and received his PhD in electrical engineering in 1965 from the University of London, under Professor Harold Barlow of University College London as an external student while working at Standard Telecommunication Laboratories (STL) in Harlow, England, the research center of Standard Telephones and Cables.

[16]: 14–15 In the 1960s at Standard Telecommunication Laboratories (STL) based in Harlow, Essex, England, Kao and his coworkers did their pioneering work in creating fibre optics as a telecommunications medium, by demonstrating that the high-loss of existing fibre optics arose from impurities in the glass, rather than from an underlying problem with the technology itself.

[37] In 1963, when Kao first joined the optical communications research team he made notes summarising the background[38] situation and available technology at the time, and identifying the key individuals[38] involved.

This conclusion opened the intense race to find low-loss materials and suitable fibres for reaching such criteria.

[citation needed] Kao, together with his new team (members including T. W. Davies, M. W. Jones and C. R. Wright), pursued this goal by testing various materials.

During this period, Kao pointed out that the high purity of fused silica (SiO2) made it an ideal candidate for optical communication.

[50] In spring 1966, Kao traveled to the U.S. but failed to interest Bell Labs, which was a competitor of STL in communication technology at that time.

He predicted in 1983 that world's seas would be littered with fibre optics, five years ahead of the time that such a trans-oceanic fibre-optic cable first became serviceable.

[56] Ali Javan's introduction of a steady helium–neon laser and Kao's discovery of fibre light-loss properties now are recognized as the two essential milestones for the development of fibre-optic communications.

[58] From 1991, Kao was an Independent Non-Executive Director and a member of the Audit Committee of the Varitronix International Limited in Hong Kong.

[64] Kao was chairman and member of the Energy Advisory Committee (EAC) of Hong Kong for two years, and retired from the position on July 15, 2000.

[69] In 2003, Kao was named a Chair Professor by special appointment at the Electronics Institute of the College of Electrical Engineering and Computer Science, National Taiwan University.

[139][140] An open letter published by Kao and his wife in 2010 later clarified that "Charles studied in Hong Kong for his high schooling, he has taught here, he was the Vice-Chancellor of CUHK and retired here too.

Beginning in 2008, he resided in Mountain View, California, United States, where he moved from Hong Kong in order to live near his children and grandchild.

Hockham's was investigating light-loss due to discontinuities and curvature of fiber.^ b: Some sources show around 1964,[152][153] for example, "By 1964, a critical and theoretical specification was identified by Dr. Charles K. Kao for long-range communication devices, the 10 or 20 dB of light loss per kilometer standard."

[50] ^ d: In the United States National Academy of Engineering Membership Website, Kao's country is indicated as "People's Republic of China".

^ b: Some sources show around 1964,[152][153] for example, "By 1964, a critical and theoretical specification was identified by Dr. Charles K. Kao for long-range communication devices, the 10 or 20 dB of light loss per kilometer standard."

[50] ^ d: In the United States National Academy of Engineering Membership Website, Kao's country is indicated as "People's Republic of China".