30 Obituaries An electrical engineer and physicist, Charles was responsible for a breakthrough in fibre optic communications which made the internet and new information age possible. In his early career, Charles saw the potential of lasers to transfer information, realising that they had signal-carrying bandwidth capabilities far greater than those of microwave carriers. He was also aware of the problems of transferring information over long distances via lasers, most notably signal loss as the atmosphere scattered the light. Working with his colleague George Hockham, Charles discovered that the signal loss in existing fibre optic cables was down to impurities in their glass. With Hockham’s support, Charles set about analysing the discontinuity and imperfection problems of the waveguide and arrived at a solution – that vapour-grown fused silica could be used to make low loss optical fibres. The discovery would, as his former colleague Professor Will Stewart put it, “cause the work on fibre communications worldwide to explode”. Charles’s interest in experimentation was apparent at a young age. In a film produced by our institution, at the time known as the Institution of Electrical Engineers (IEE), Charles recalled his first titration experiment at the age of 10. He noted that he “had watched fascinated the litmus paper changing from blue to red and vice versa”, but that he had found something even more remarkable when he returned to experiment the next morning. “Perhaps it was the sparkling perfect blue crystals of copper sulphate in the petri dish that began my interest in experimentation,” he said. At the age of 19, Charles started studying electrical engineering at Woolwich Polytechnic, during which time he became a member of the IEE. After graduating, he joined the British subsidiary of International Telephone & Telegraph (ITT), where he would spend the next three decades and meet his future wife, Gwen Wong. When he was transferred to the company’s central research laboratory, Standard Telecommunication Laboratories (STL) in Essex, his focus on optical communication problems intensified. This resulted in publication of his landmark paper with George Hockham, in 1966, which changed the course of our communication systems. In the following years, Charles saw his ideas transformed into reality, as his research fuelled the development of products. He took a four-year sabbatical with The Chinese University of Hong Kong between 1970-74, but returned to ITT in the USA to work on transferring optical fibre communication system technology from research and development to commercially viable products. “Today we are installing over 300 million km (a thousand times the Earth-Moon distance) of silica, of the type Charlie envisaged, every year,” said Professor Stewart. He continued:. The vast bulk of communication systems, from wireless and mobile devices like smartphones to data centres for web services, rely on optical fibres.” Charles’s contributions to society were gradually recognised, with the IEE Faraday Medal in 1989, the Nobel Prize in 2009 and a knighthood in 2010. Besides his impressive achievements, Charles’s colleagues remember him for his support to the professional community. “He was an inspiring person, and was always encouraging and supportive of young researchers,” said Professor Stewart. “Though an intellectually big human being, he contributed personally to make the world a smaller and more accessible place.” Charles leaves behind his wife Gwen and two children, Amanda and Simon. For a full list of obituaries visit theiet.org/mn-obituaries Charles Kao FIET at Standard Telecommunication Laboratories, setting up his optical bench to investigate waveguides, 1966 Sir Charles Kuen Kao KBE CBE FREng FIET Charles Kao, an IET Fellow who won the Nobel Prize for his groundbreaking research on fibre optics, has died at the age of 85. November 1933 – September 2018 Member News March 2019