Bulletin Special Supplement on Prof. Charles K. Kao, Former Vice-Chancellor and Nobel Laureate The Love and Labour of a Laureate

Foreword 5 But there were obstacles and they were huge. One was getting a beam of light to travel from A to B. A torch shone at a window is visible on the other side, but one shone at glass 100 m thick would be lost in transmission. Professor Kao’s conjecture was that the dimming of light passing through the glass fiber was due not to intrinsic absorption by the glass, but to impurities in it. Hence if the impurities could be removed, one should be able to see through a slab several hundred metres thick. That insight, which Professor Kao proved by careful measurements, ushered in the dawn of optical communications. Today it is possible for 95 per cent of the light to remain after having travelled a full kilometre in glass. In 1966, Professor Kao presented his ideas at a meeting of the Institute of Electrical Engineers (IEE) and then wrote up the findings in a paper titled ‘Dielectric-Fiber Surface Waveguides for Optical Frequencies’, published in the Proceedings of IEE in July 1966. The date is now regarded as the birthday of optical fiber communication, but it had taken Professor Kao years to convince the world that a concept of such magnitude was in fact practical. In 1970, inspired by his enthusiasm, scientists at Corning Glass Works unveiled a fiber-optic strand that had the ability to carry a high-speed signal over 1 km. So the light came, and all shadow was dispelled between the idea and reality. And the rest, as they say, is history. Looking into the future (Photo: South China Morning Post)