Nobel Awarded for Harnessing Light
Our ubiquitous Digital cameras, YouTube, hi-speed Internet, medical endoscopes —just a few of countless modern marvels made possible by the three scientists who won the 2009 Nobel Prize in physics
Charles Kuen Kao and with Willard Sterling Boyle and George Elwood Smith sharing the other half. Kao’s discoveries have paved the way for optical fiber technology, which today is used for almost all telephony and data communication. Boyle and Smith have invented a digital image sensor – CCD, or charge-coupled device – which today has become an electronic eye in almost all areas of photography.
Read an excerpt from NYT..
According to the academy in its prize announcement, the optical cables in use today, if unraveled, would equal a fiber more than 600 million miles long.
In September 1969, Dr. Boyle and Dr. Smith, working at Bell Labs in Murray Hill, N.J., sketched out an idea on a blackboard in Dr. Boyle’s office. “He had a bigger office than me,” Dr. Smith recalled in a telephone interview. “The two of us frequently got together just to kick ideas around.”
Their idea takes advantage of the photoelectric effect, which was explained by Albert Einstein and won him the Nobel in 1921. When light hits a piece of silicon, it knocks out electrons. The brighter the light, the more electrons are knocked out.
The two were initially brainstorming how to make a new type of electronic memory. “But in my first notebook entry,” Dr. Smith said, “I fully described how we would use it as an imaging device as well.”
In a CCD, the knocked-out electrons are gathered in small wells, where they are counted — essentially one pixel of an image. The data from an array of CCDs can then be reconstructed as an image. The technology was intended for a picture phone but the project was canceled, and Dr. Boyle and Dr. Smith moved on to other research topics even as CCDs began to spread around the planet.
“We are the ones, I guess, that started this profusion of little small cameras working all over the world,” Dr. Boyle said. A 10-megapixel camera contains 10 million CCDs.
Besides consumer cameras, CCDs also made possible the cosmic panoramas from the Hubble Space Telescope and the Martian postcards taken by NASA landers.
Also eloquently explained by Nobel Foundation’s Press Release
Illuminating Information Sharing
If you’re reading this online, and if you have just been surveying portraits of the new Nobel Laureates, then it’s safe to say that you’re benefitting directly from the two achievements rewarded with the 2009 Nobel Prize in Physics. The optical fibers along which this Speed Read is travelling, and the digital imaging which underlies practically all modern photography, are the direct consequences of that work, done 40 years ago.
Optical fiber communication is now ubiquitous, but when Charles Kao first suggested that glass fibers could be used for long range information transfer, his ideas were met with scepticism. It had long been understood that glass fibers could act as waveguides for light, allowing, for instance, the development of short range optical fibers for probing the inner recesses of our bodies. But such fibers were thought to be far too inefficient for any long range use, light transmission falling to negligible levels after just a few meters.
In a 1966 paper, Kao and his colleague George Hockham put forward the radical suggestion that impurities in the glass were responsible for this inefficiency, and that truly pure glass would give vastly improved light transmission. When, four years later, optical fibers of pure glass were at last fabricated, Kao and Hockham’s prediction was found to be correct, paving the way for the development of today’s ubiquitous, efficient, energy-saving optical cable networks.
Digital image capture, now so much a part of everyday life, got its start from an afternoon’s brainstorming between Willard Boyle and George Smith, colleagues at the famous Bell Laboratories. Working in the semiconductor division, in 1969 they were asked by their boss to come up with a novel technology for information storage. The device they sketched on the board that afternoon was an image sensor based on Albert Einstein’s photoelectric effect, in which arrays of photocells would emit electrons in amounts proportional to the intensity of incoming light. The electron content of each photocell could then be read out, transforming an optical image into a digital one. Their charge-coupled device (CCD), as they named it, proved not to have a future in memory storage, but rather gave rise to an explosion in digital imaging, with the first CCD-based video cameras appearing in the early 1970s. Although CCDs are to some extent now supplemented by competing technologies, their use in applications ranging from digital cameras to the Hubble space telescope has completely transformed image processing.
Adam Smith, Editor © Nobelprize.org