Like runners racing to a finish line, a burst of photons fired into some glass fibers arrive at the end as a drawn-out blur. In today's computer networks, those optical fibers in which such smearing, or dispersion, is great are used to carry only a limited volume of data per fiber and only for relatively short hauls. Nonetheless, these fibers align easily with lasers, so systems using them are comparatively inexpensive and popular.
Now, Howard R. Stuart of Lucent Technologies' Bell Labs in Holmdel, N.J., has found a way to transform the Achilles heel of these so-called multimode fibers into a source of new strength. Using several lasers to send data and as many detectors to receive it, Stuart expects to multiply bit flow by the number of lasers, he says. No longer a curse, dispersion becomes the key to unraveling the data threads at their destination, he notes.