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Wednesday, October 07, 2009

Stories of the 2009 Nobel Prize in Physics

I got interested in the 2009 Nobel Prize in Physics for obvious reasons: the winner of 1/2 of the prize, Charles Kao, is of Chinese origin and I think I know his younger brother. But this super New York Times article told the background stories of all three winners and made their accomplishments easily understandable, even to me:

Fiber optic cables and lasers capable of sending pulses of light down them already existed when Dr. Kao started working on fiber optics. But at that time, the light pulses could travel only about 20 meters through the glass fibers before 99 percent of the light had dissipated. His goal was to extend the 20 meters to a kilometer. At the time, many researchers thought tiny imperfections, like holes or cracks in the fibers, were scattering the light.

In January 1966, Dr. Kao, then working at the Standard Telecommunication Laboratories in England, presented his findings. It was not the manufacturing of the fiber that was at fault, but rather that the ingredient for the fiber — the glass — was not pure enough. A purer glass made of fused quartz would be more transparent, allowing the light to pass more easily. In 1970, researchers at Corning Glass Works were able to produce an ultrapure optical fiber more than a half-mile long.

A news release from the Chinese University of Hong Kong, where Dr. Kao worked as a professor and later a vice chancellor, quoted Dr. Kao’s reaction: “This is very, very unexpected. Fiber optics has changed the world of information so much in these last 40 years. It certainly is due to the fiber optical networks that the news has traveled so fast.”

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.
Now the other 1/2 of the prize shared by Willard S. Boyle and George E. Smith, for inventing the semiconductor sensor known as a charge-coupled device, or CCD.

In January 1966, Dr. Kao, then working at the Standard Telecommunication Laboratories in England, presented his findings. It was not the manufacturing of the fiber that was at fault, but rather that the ingredient for the fiber — the glass — was not pure enough. A purer glass made of fused quartz would be more transparent, allowing the light to pass more easily. In 1970, researchers at Corning Glass Works were able to produce an ultrapure optical fiber more than a half-mile long.

A news release from the Chinese University of Hong Kong, where Dr. Kao worked as a professor and later a vice chancellor, quoted Dr. Kao’s reaction: “This is very, very unexpected. Fiber optics has changed the world of information so much in these last 40 years. It certainly is due to the fiber optical networks that the news has traveled so fast.”

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.
Well, we all use internet and digital cameras daily without any hesitation, it's just part of our modern life now. It will not be the case without the ingenious contributions of these three scientists. They are certainly most deserving -- may be a little belated by about 40 years. Of course better late than never. They have all been amply honored in their life from many other sources. But a Nobel is still the brightest of them all!

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