Rochester researchers develop flexible optical switch

17 Jun 2002

A device that has the potential to remove a major bottleneck between optical networks has been built by researchers from the University of Rochester. Engineers hope the device will allow fast optical data conversion that could spur the development of extensive local fiber-optic communications networks.

Researchers created the device, which has no moving parts, from off-the-shelf components, making it much less expensive to produce than competing devices that need complicated, custom-designed parts. The university, together with its co-developer, the University of Tokyo, has recently applied for a joint patent on the device, called an optical flip-flop switch.

"What makes this switch special is its speed and flexibility," says Govind Agrawal, professor of optics and co-inventor of the device. "This kind of device is something the communications industries have been looking for for a long time."

The new switch is also good at removing another hurdle that slows the junction of optical networks. Different networks use different lengths of pulses; the new switch operates so quickly that it can customize the length of the pulses by simply varying the time before "shutting the shade". Leaving the shade open a little longer results in a longer pulse; shutting it sooner makes a shorter pulse, allowing any network to receive the exact pulse length it needs.

One of the surprising aspects of this device is that all of its parts have been commercially available for years. "Everything we needed to build this was there all along," says Drew Maywar, an optics doctoral candidate at the University of Rochester's Institute of Optics and co-inventor of the switch. "It's just that no one ever thought of doing it this way before."

One of the breakthroughs in the design of the switch came to Maywar while he was visiting the University of Tokyo as part of his graduate research. He was trying to explain the workings of conventional switches to another student when it dawned on him that if he could find a way to reverse the "opening of the shade", he could develop an ultra-fast switching device.

Nine months later he had a working prototype.

"A lot of people told me I was foolish to pursue my idea," he says. "They thought there was no way the weak light in an optical fiber would be enough to reverse the process."

Maywar used his experience in basic optical science from the University of Rochester with the available technology at the University of Tokyo to build the prototype just before returning to Rochester.