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

22  Chinese University Bulletin Special Supplement 2010  dead of night when the air was still and even with refocusing ever y 100 metres, the beam refused to stay within the lens aperture. Bell Labs experiments using gas lenses were abandoned due to the difficulty of providing satisfac tor y insulation while maintaining the profiles of the gas lenses. These experiments were struggles in desperation, to control light travelling over long distances. At STL the thinking shifted towards dielectric waveguides. Dielectric means a non- conductor of electricity; a dielectric waveguide is a waveguide consisting of a dielectric cylinder surrounded by air. Dr. Karbowiak suggested Charles and three others to work on his idea of a thin film waveguide. But thin film waveguides failed: the confinement was not strong enough and light would escape as it negotiates a bend. When Dr. Karbowiak decided to emigrate to Australia, Charles took over as the project leader and he then recommended that the team should investigate the loss mechanism of dielectric materials for optical fibers. A small group worked on methods for measuring material loss of low-loss transparent materials. George Hockham joined him to work on the characteristics of dielectric waveguides. With his interest in waveguide theory, he focused on the tolerance requirements for an optical fiber waveguide; in particular, the dimensional tolerance and joint losses. They proceeded to systematically study the physical and waveguide requirements on glass fibers. In addition, Charles was also pushing his colleagues in the laser group to work towards a semiconductor laser in the near infrared, with emission characteristics matching the diametre of a single-mode fiber. Single mode fiber is optical fiber that is designed for the transmission of a single ray or mode of light as a carrier. The laser had to be made durable, and to work at room temperatures without liquid nitrogen cooling. So there were many obstacles. But in the early 1960s, esoteric research was tolerated so long as it was not too costly. Over the next two years, the team worked towards the goals. They were all novices in the physics and chemistry of materials and in tackling new electromagnetic wave problems. But