Charles Kuen Kao

A Chinese-born electrical engineer and physicist, Kao held multiple citizenship of Hong Kong, the United Kingdom, and the United States. He pioneered the development and use of fiber optics in telecommunications and is known as the "Godfather of Broadband," "Father of Fiber Optics," or "Father of Fiber Optic Communications." He was jointly awarded the 2009 Nobel Prize in Physics for "groundbreaking achievements concerning the transmission of light in fibers for optical communication."

Born in Shanghai, his ancestral home was in nearby Jinshan. He studied Chinese classics at home with his brother, under a tutor. Kao also studied English and French at an international school in Shanghai which was founded by a number of progressive Chinese educators including Cai Yuanpei. His family moved to Hong Kong in 1948, where he completed his secondary education (advanced level) at St. Joseph's College in 1952.

He did his undergraduate studies in Electrical Engineering at Woolwich Polytechnic (now the University of Greenwich), a British, London-based university, obtaining his Bachelor of Science degree. He then pursued research and received his Ph.D. degree in Electrical Engineering in 1965 from University College London (under Professor Harold Barlow) as an external student while working at Standard Telecommunication Laboratories (STL) in Harlow, England, the research center of Standard Telephones and Cables. It was there that Kao did his first groundbreaking work as an engineer and researcher, working alongside George Hockham under the supervision of Alec Reeves.

He joined The Chinese University of Hong Kong (CUHK) in 1970 to found the Department of Electronics, which later became the Department of Electronic Engineering. During this period, he served as Reader and then Chair Professor of Electronics at CUHK, where he built up both undergraduate and graduate study programs in electronics and saw the graduation of his first students. Under his leadership, the School of Education and other new research institutes were established.

He then went back to ITT Corporation in 1974 (the parent corporation of STC at that time) in the United States and worked in Roanoke, Virginia, first as Chief Scientist and later as Director of Engineering. In 1982, Kao became the first ITT Executive Scientist and was stationed mainly at the Advanced Technology Center in Connecticut. While there, he served as an adjunct Professor and Fellow of Trumbull College at Yale University. In 1985, he spent one year in West Germany at the SEL Research Centre, and in 1986 he served as Corporate Director of Research at ITT.

He served as Vice-Chancellor (President) of the Chinese University of Hong Kong from 1987 to 1996. After his retirement from CUHK in 1996, he spent a six-month sabbatical leave at the Imperial College London Department of Electrical and Electronic Engineering; from 1997 to 2002, he also served as Visiting Professor in the same department. From 1993 to 1994, Kao was President of ASAIHL (The Association of Southeast Asian Institutions of Higher Learning).

He subsequently worked as Chairman and CEO of Transtech Services Ltd., a telecommunication consultancy company in Hong Kong, and was the founder, Chairman, and CEO of ITX Services Limited. From 2003 to January 30, 2009, he served as an Independent Non-executive Director and Member of the Audit Committee of Next Media. From 1991, he served as an Independent Non-Executive Director and member of the Audit Committee of Varitronix International Limited in Hong Kong.

In 2000, he founded the Independent Schools Foundation Academy (ISF), located in Cyberport, Hong Kong, serving as its founding Chairman and stepping down from the Board of the ISF in December 2008. He was the keynote speaker at IEEE GLOBECOM 2002 in Taipei, Taiwan. 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.

He met his future wife, British Chinese May-Wan Kao (née Wong), in London after graduation. She was a Fortran programmer who worked in the same factory as he did. They were married in 1959 in London and had two children, a son and a daughter, both of whom reside and work in Silicon Valley, California.

In the 1960s at Standard Telecommunication Laboratories (STL) in Harlow, Essex, Kao and his co-workers did their pioneering work in the realisation of fiber optics as a telecommunications medium, demonstrating that the high loss of existing fiber optics arose from impurities in the glass, rather than from an underlying problem with the technology itself. Initially he worked in the team of Antoni E. Karbowiak (Toni Karbowiak), who was working under Alec Reeves to study optical waveguides for communications. His task was to investigate fiber attenuation, for which he collected samples from different fiber manufacturers and also investigated the properties of bulk glasses carefully. This study primarily convinced him that impurities in the material caused the high light losses of those fibers.

In 1963, he was appointed head of the Electro-Optics Research Group at STL. Kao took over the Optical Communication Program of STL in December 1964, because his supervisor, Karbowiak, left to take the Chair in Communications in the School of Electrical Engineering at the University of New South Wales (UNSW), Sydney, Australia. Although he succeeded Karbowiak as Manager of Optical Communications Research, he immediately decided to abandon Karbowiak's plan (thin-film waveguide) and broadly change the research direction with his colleague George Hockham. They not only considered optical physics but also the material properties.

He first presented the results to the IEE in January 1966 in London, and further published in July with George Hockham (1964–1965). This study first theorized and proposed the use of glass fibers to implement optical communication; the ideas described — especially structural features and materials — are largely the basis of today's optical fiber communications. In 1965, Kao, along with Hockham, concluded that the fundamental limitation for glass light attenuation is below 20 dB/km (decibels per kilometer, a measure of the attenuation of a signal over a distance), which is a key threshold value for optical communications. However, at the time of this determination, optical fibers commonly exhibited light loss as high as 1,000 dB/km and even more. This conclusion opened an intense race to find low-loss materials and suitable fibers for reaching such criteria.

He, together with his new team (members including T.W. Davies, M.W. Jones, and C.R. Wright), pursued this goal by testing various materials. They precisely measured the attenuation of light at different wavelengths in glasses and other materials. During this period, Kao pointed out that the high purity of fused silica (SiO2) made it an ideal candidate for optical communication. He also established that the impurity of glass material was the main cause of the dramatic decay of light transmission inside glass fiber, rather than fundamental physical effects such as scattering as many physicists believed at that time, and that such impurity could be removed. This led to a worldwide study and production of high-purity glass fibers.

When he first proposed that such glass fiber could be used for long-distance information transfer and could replace copper wires then used for telecommunication, his ideas were widely disbelieved; people later realized that Kao's ideas revolutionized the whole communications technology industry. He played a leading role in the early stage of engineering and commercial realization of optical communication. In spring 1966, he traveled to the U.S. but failed to interest Bell Labs, which was a competitor of STL in communication technology at that time. He subsequently traveled to Japan and gained support, visiting many glass and polymer factories and discussing techniques and improvements in glass fiber manufacture with engineers, scientists, and businessmen.

In 1969, he, along with M.W. Jones, measured the intrinsic loss of bulk-fused silica at 4 dB/km, which was the first evidence of ultra-transparent glass. Bell Labs started considering fiber optics seriously after this finding. Kao developed important techniques and configurations for glass fiber waveguides and contributed to the development of different fiber types and system devices which met both civil and military application requirements, as well as peripheral supporting systems for optical fiber communication. In the mid-1970s, he did seminal work on glass fiber fatigue strength.

When named the first ITT Executive Scientist, he launched the "Terabit Technology" program addressing the high-frequency limits of signal processing; he is therefore also known as the "Father of the Terabit Technology Concept." He published more than 100 papers and was granted over 30 patents, including water-resistant high-strength fibers (with M.S. Maklad). At an early stage of developing optic fibers, Kao strongly preferred single mode for long-distance optical communication, instead of using multi-mode systems. His vision was later followed and is now applied almost exclusively.

He was also a visionary of modern submarine communications cables and largely promoted this idea. He predicted in 1983 that the world's seas would be littered with fiber optics, five years ahead of the time that such a trans-oceanic fiber-optic cable first became serviceable. Ali Javan's introduction of a steady helium–neon laser and Kao's discovery of fiber light-loss properties are now recognized as the two essential milestones for the development of fiber-optic communications.

He was one of the earliest to study the environmental effects of land reclamation in Hong Kong and presented one of his first related studies at the conference of ACU (Association of Commonwealth Universities) in Edinburgh in 1972. He served as Chairman and Member of the Energy Advisory Committee (EAC) of Hong Kong for two years, retiring from the position on July 15, 2000. Kao also served as a Member of the Council of Advisors on Innovation and Technology of Hong Kong, appointed on April 20, 2000. He received numerous honors and awards throughout his life, the most notable being the Nobel Prize in Physics.