October 9, 2009

Alum shares physics Nobel for digital photo technology

George E. Smith (S.M. ’56, Ph.D. ’59) received the Nobel Prize for Physics Tuesday for co-inventing a circuit that turns light into electric signals. The device, called the “electronic eye” of digital cameras by the Nobel Committee, is also used in telescopes, like the Hubble telescope, and medical devices.

Smith invented the charge-coupled censor (CCD) with Willard S. Boyle when they both worked at Bell Labs in 1969. They shared this year’s $1.4-million prize with Charles K. Kao, who developed fiber optics, thin glass tubes that transmit light signals over long distances.

The Royal Swedish Academy of Sciences called the three winners “masters of light [who] helped shape the foundation of today’s networked societies.”

Photons hitting a CCD create a charge on its surface by knocking electrons out of orbit. These charges, of varying strengths depending on the brightness of the light, can be transported across the semi-conductor and later read together as a collection of pixels to create an image.

CCDs allow digital cameras to take better quality pictures than conventional film by picking up more available light. A single photon hitting a CCD will create a charge 80 percent of the time, while it can take up to 100 photons to break the bonds in film.

Boyle and Smith were working on a picture phone—a low resolution TV screen that could make calls—when their boss threatened to transfer their funding to a rival research group unless they could come up with a better way to store digital information.

In less than an hour, Boyle and Smith sketched out the basic structure of a CCD, which was designed as a series of wells, each storing one bit of memory. They soon realized that instead of feeding information to the CCD, they could use light to create signals.

“Bill and I really enjoyed batting things around,” Smith said in 2001, as part of an oral history project with the Institute of Electrical and Electronics Engineers.

Smith graduated from the University of Pennsylvania in 1955, after spending four years in the Navy. It was at school that he discovered he was interested in science with practical applications.

“Esoteric math was too esoteric for me,” Smith said. “I wanted to get my hands dirty and went into experimental physics.”

For graduate work, Smith came to the U of C, which had a “very good physics department,” he said. He worked at the University’s Institute of Metals—now known as the James Franke Institute.

“I got through Chicago in four years, going from a master’s to a Ph.D., which was kind of fast,” he said. “I also had the shortest dissertation on record in the physics department.”

AT&T Bell Labs soon hired Smith, where he spent his entire career before retiring in 1986. Smith worked primarily with semi-conductors, though AT&T encouraged research even if it wouldn’t have a direct impact on telephone technology.

“Essentially we were supposed to see if we could invent the wave of the future.” Smith said. “There was a rule of thumb that if 90 percent of what you were doing was not a failure then you were not being bold enough.”

With Smith’s win, 29 physics Nobel laureates worked or studied at the University, including last year’s co-winner, former professor Yochiru Nambu.