For students, blazing-fast lab work

Consider a device the size of a grain of salt that can process information a billion times faster than the human brain. Inspired by animal nervous systems, the “photonic neuron” uses light instead of electrochemical impulses to process information at lightning-quick speeds.

And in the lab of electrical engineering professor Paul Prucnal, it’s becoming a reality. “It’s a way of encoding more information and processing it more quickly,” Prucnal said.

Alex Tait ’12, one of the lab’s summer interns, has contributed a device that acts as the decision-making part of the neuron. It’s called the double ring enhanced asymmetric Mach-Zehnder interferometer. (Thankfully, it makes an easy acronym: They call it the DREAM device.)

But more on that later. Before there was a DREAM, there were meetings — and the occasional free pizza. Tait, along with William Herlands ’12, Mitchell Nahmias ’12, and Nicole Rafidi ’12, are almost two years into the project, a research collaboration with aerospace and defense company Lockheed Martin that began in 2008. The seniors first became involved as sophomores, attending weekly meetings in Prucnal’s lab.

“They just came to the meetings and hung out,” Prucnal said. “The students would sit and listen, like a seminar, but also began offering suggestions and taking courses in neuroscience — and pretty soon became experts themselves.”

For now the lab is filled with boxes and fiber-optic cables — off-the-shelf technology that allows the team to experiment. Next year’s plan is to integrate microscopic versions of the photonic neuron on a microchip. The ultimate goal is to make a signal processor that functions the way an animal neural circuit does — with decision-making and learning — but at the speed of light. Already the lab has built a photonic circuit that mimics the basic neural circuit that crayfish use to escape danger.

The technology eventually might be used to help in tasks that require a lot of computational power or extremely quick decision-making, like processing large amounts of surveillance video or ejecting a pilot from a jet plane.

The four seniors have become an integral part of Prucnal’s lab, where undergraduates, graduate students, and postdocs work throughout the year. This summer, Tait and Nahmias stayed on campus to work on the project.

Undergraduates have had the opportunity not only to present their work at a conference in Santa Fe, N.M. (where Prucnal said they “created quite a stir”), but also to contribute to a new technology. Which brings us back to the DREAM device, Tait’s senior-thesis project and the fruits of his summer research. The device, which distinguishes relevant signals from noise, has seen major contributions from all of the students. It’s a “breakthrough,” Prucnal said.

“It’s a really great experience for undergrads because it’s so new,” Tait said. “There haven’t been 40 years of people looking at the same problem — we have the first crack at it.”