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UWM researchers create novel optical fibers

Ordering the march of photons that carry the world's information.

UWM researchers create novel optical fibers by Laura L. Otto

Before the next generation of high-speed communication and biomedical imaging can be realized, researchers must first find ways to transport more data through optical fibers.

Arash Mafi, an associate professor of electrical engineering, wondered if one solution might be a curious phenomenon that had been observed in 1958, but has never been put to practical use: Anderson localization.

The phenomenon is named for physicist Philip W. Anderson, who first theorized the “trapping” of electrons in a highly disordered medium, work that earned a Nobel Prize in 1977.

In a commonly used single-core fiber, only one spatial channel of light traverses through. That limits the information-carrying capacity.

Arash Mafi, Associate Professor of Electrical Engineering

Mafi and graduate student Salman Karbasi decided to apply the phenomenon in the work they were doing to improve the performance of optical fibers. The research has tremendous potential: Data transmission through conventional optical fibers is the backbone of the Internet.

“In a commonly used single-core fiber, only one spatial channel of light traverses through. That limits the information-carrying capacity,” says Mafi, who worked as a scientist at Corning Incorporated, the world’s largest manufacturer of optical fibers.

Mafi and Karbasi have found that Anderson localization is one way of propagating multiple beams in a single strand of optical fiber.

Arash Mafi

Arash Mafi

Karbasi’s fiber architecture brought the idea to life. The design consists of two randomly distributed materials that increase the scattering of photons within the fiber.

Karbasi’s calculations indicated Anderson localization would occur within this disordered interior, causing a beam of light traveling through it to freeze laterally. His design worked, and also allowed multiple frozen beams to pass through a single fiber.

“We designed our fiber so that it provides more physical places where the light can propagate,” says Karbasi of the project, which also includes Karl Koch, a scientist with Corning.

The opportunity to work alongside Mafi, winner of a CAREER grant from the National Science Foundation, is the reason Karbasi chose to study at UWM.

“When I’m involved in doing the experiment, my mind is busy,” Karbasi says. “But the time I spend doesn’t always end in a resolution I expect. That’s when I often get the best ideas.”