Nobel prizes recognise importance of optics

The Nobel Prize committee, which each year awards prizes for achievements in the sciences and humanities, have this year given their recognition to the role of optics in transforming the world of information technology^†.

CCD array ^‡

Half of the 10m Swedish Krona prize for physics goes to Charles Kao, who is affiliated with the Standard Telecommunication Laboratories, Harlow, in the UK, and with the Chinese University of Hong Kong. The prize was awarded for his work on optical fibres in the 1960's, which described the necessary material properties of glass which would enable fibres made from it to transmit information. Optical fibres at the time were impractical for long distance communication and were limited to light transmission over just a few metres. By increasing the purity of the glass and thereby reducing the absorption and scattering of light, Kao showed that glass was capable of carrying light signals over distances spanning several kilometres.

These fibres became a reality in the early 1970's and rapid developments ensued, accelerated in part by the concurrent advances in LED's and lasers. The massive industrial growth of fibre optics has brought us to the the point where it now forms the very bedrock of our telecommunications infrastructure, including the internet, which would not exist today in its present form without the high bandwidths made possible by light.

The other half of this year's Nobel prize goes to Willard S. Boyle and George E. Smith of Bell Laboratories in the USA. Together they invented the charge-coupled device (CCD), a light sensor which, in its most familiar form, has revolutionised the world of photography, rapidly usurping the emulsion film which had reigned for so long.

CCD detectors are built from silicon and are comprised of individual light sensors in a two dimensional array. These sensors produce electron charges when light falls on them, which can then be read out electronically in a rapid and efficient manner. Originally conceived of as a memory storage device, Boyle and Smith had actually devised a new imaging technology. Not only does it provide a convenient method for storing and transmitting images electronically, it is also far more sensitive than photographic film. Camera phones, medical diagnostic tools and space telescopes are just some of the applications in which we see CCD's used today.