May 2001

The Next Generation of Optical Fibers

Continued from page 4

By Philip Ball

Photonic Finish

Taking on existing optical fibers will be a tall order. Conventional glass fibers have been optimized over several decades and are made using well-entrenched technology. In contrast, the new photonic fibers represent a manufacturing unknown. For one thing, their structure must be exact. "The existing [fabrication] systems are simply not up to it," admits Russell.

Still, companies are lining up to meet the commercialization challenges. Fink says OmniGuide is working on a series of products based on different-length fibers. Projects include the development of active fiber-based devices for optical switching, as well as the development of fibers for light transmission over 10 to 100 meters, which could be useful for tasks such as connecting servers over short distances. Long-haul fibers for telecom networks will have the biggest impact, says Fink, but these "will take a little time."

Researchers from the Bath group have launched their own spinoff, BlazePhotonics, and have secured funding from venture capital firms in the United Kingdom and United States. In Denmark a company called Crystal Fibre, started by scientists at the Technical University of Denmark in Lyngby who were early collaborators with the Bath group, is making photonic fibers with a solid glass core. While its initial products might serve such purposes as confining light in high-precision lasers, no one is losing sight of the big prize. "Telecommunications is definitely the medium-term target," says CEO Michael Kjaer.

Like the founders of Denmark's Crystal Fibre, scientists at Corning have worked closely with the Bath researchers in the past, but they are now racing to the marketplace on their own. Jim West reports the company can now make photonic fibers up to a hundred meters long. But he reserves judgment about whether the new materials will eventually transform the information superhighway. Conventional optical fibers, he points out, are a difficult act to top. "It's only when you start working with the state-of-the-art versions that you realize how remarkable they are."

Although sending light through air may solve many of the limitations of today's fibers, it poses its own problems. For one thing, the composition of air is not uniform; as a result, light may be transmitted differently in different parts of the world. "Air in the U.K. is very different from air in the Sahara," explains West.

"It's a fascinating technology," says West of the new generation of photonic crystal fibers, "but there is a long way to go."

Still, if these new materials eventually fulfill their potential of transforming long-distance transmission in the telecommunications industry, it will be a journey well worth taking.