Talking with light: Brady sees growth in photonics

January 19, 2002

by Monte Basgall

In his futuristic office in Hudson Hall, David Brady uses computers and remote closed-circuit TV links to project images on screens throughout the room. This way, he can observe several events at once at distant out-of-state locations.

This proved helpful earlier this year, when he monitored his family's progress as they moved from Illinois to Durham.

"I can see what's going on in different places," the Brian F. Addy Endowed Director of Duke's new Fitzpatrick Center for Photonics and Communications Systems said. "Those are my virtual windows."

Brady, who is also a professor of electrical and computer engineering in the Pratt School of Engineering, wants to help the outside world get similarly connected to facts, ideas and places. His goal is on-demand availability of information, anywhere and anytime, through the power of technology and versatility of light.

Photonics is a field that exploits the uses of light for communications. It already has spawned major industries, such as fiberoptic cables to convey light for telephone communications, and routers and switches to channel such optical signals in discrete bunches. Experts say its down-the-road potential will dwarf current applications.

With a $25 million donation from high-tech entrepreneur Michael J. Fitzpatrick and his wife Patty, Duke's Pratt School of Engineering and Brady hope to spearhead the directions of futuristic photonics research.

"Around 1970, when I was a little kid, we got a color TV, and that was an exciting thing," he recalled. "In my house today, we have more television sets than there are individuals living there. I like to watch games and I'll wander from room to room looking at a game in different rooms. And that's really just scratching the surface of displays in the house.

"Those are portals into an information world. So I think it's a very exciting time."

Brady envisions a world where personal devices such as Palm Pilots or even desktops will often be unnecessary. Instead, people might walk up to a flat panel screen built into a wall of their local mall and access any files they want with the aid of a special identification scanner.

"There's no reason why your interface with computer networks should consist of just a desktop machine and a keyboard," he added. "All your information could be pulled to displays embedded in the environment, so you wouldn't need to be carrying any sort of device."

Going even further, he and his research colleagues -- some of whom have followed him to Duke from the University of Illinois at Urbana-Champaign -- are analyzing the very ways people access information through their eyes or via cameras.

The fact that the human eye has higher resolution in its center than elsewhere means people see more than they can actually register, he noted. "If you can track what users are looking at and just give them sharp images in the middle, they won't notice that has happened but network resources will be more efficiently used."

His research group also is challenging the very nature of what a camera does. Back in Champaign, he co-founded Distance Focus Corp. to make special digital cameras with built-in computerized processors and networking components, mainly for security and defense uses.

When Brady enrolled in Macalester College in St. Paul, Minn., in 1981, he planned to be a business major. Then three crucial things happened.

First, "I took physics classes," he said.

He also was moved by a Scientific American article on computing with light.

And he met Rachael Buhse, another Macalester mathematics and physics major who eventually became his wife and is now a research scientist at Duke studying another application of computers and light called virtual reality.

The magazine piece got him especially excited about the concept of optical "fields," invisible domains through which vibrating light waves move. "I can't imagine studying anything more interesting," he said. "What we study is how we transform them, how they propagate and how information is conveyed on these fields as it goes through fibers or a variety of spaces."

After Macalester, both he and Buhse went to California, he enrolling at Caltech and she at the University of California at Berkeley. By the time the Bradys married in 1986, he had embarked on graduate work about how neural networks -- computer connections that mimic those of nerve cells -- could be applied to optical computing. The tie was special three-dimensional kinds of holograms. Holography is a method for storing and displaying images, usually with a laser beam.

It was at a 1988 neural network conference in France that Brady first met Kristina Johnson, now dean of the Pratt School and at the time a researcher at National Science Foundation engineering research center for optical computing at the University of Colorado at Boulder.

After he receiving a doctorate from Caltech in 1989, Brady was recruited by the multi-disciplinary Beckman Institute for Advance Science and Technology at the University of Illinois at Urbana-Champaign. He also joined the university's electrical and computer engineering faculty.

"I was recruited into the Beckman Institute in large part because of my background in neural networks," he said. "But I never worked on neural networks again."

Instead, he decided that the short-term prospects for light computing -- light essentially substituting for the electricity of conventional computers -- are lower than those for using light in communications. He became a leader of the Beckman Institute's Photonics Systems Group, studying ways to better collect, manage and traffic light-borne information. That paved the way for both Bradys to be recruited to Duke as the university's photonics initiative blossomed.

"It's very energizing to move," he said. "You get a lot of ideas. Research is a funny business. You don't predict when interesting things will happen. But I do feel like we've discovered things in the last few months that I find are very interesting and surprising."