The Nobel Foundation today announced the winners of the Physics Prize 2009. Charles K. Kao is awarded one half of the prize “for groundbreaking achievements concerning the transmission of light in fibers for optical communication” and Willard S. Boyle and George E. Smith are sharing the second half “for the invention of an imaging semiconductor circuit – the CCD sensor” (Charge-Coupled Device). Beside being the central imaging unit in every digital consumer camera, CCD’s are central to modern endoscopes, colonoscopes, ingestable video capsules, mentioned earlier today, and in a great deal of other imaging applications in medicine. Then, of course, every modern hospital is full of fiber optic cables linking it to the rest of the world.
In 1966, Charles K. Kao made a discovery that led to a breakthrough in fiber optics. He carefully calculated how to transmit light over long distances via optical glass fibers. With a fiber of purest glass it would be possible to transmit light signals over 100 kilometers, compared to only 20 meters for the fibers available in the 1960s. Kao’s enthusiasm inspired other researchers to share his vision of the future potential of fiber optics. The first ultrapure fiber was successfully fabricated just four years later, in 1970.
A large share of the traffic is made up of digital images, which constitute the second part of the award. In 1969 Willard S. Boyle and George E. Smith invented the first successful imaging technology using a digital sensor, a CCD (Charge-Coupled Device). The CCD technology makes use of the photoelectric effect, as theorized by Albert Einstein and for which he was awarded the 1921 year’s Nobel Prize. By this effect, light is transformed into electric signals. The challenge when designing an image sensor was to gather and read out the signals in a large number of image points, pixels, in a short time.