Researchers Double Fiber Optic Capacity Limit

Fiber optics offer incredibly fast data transfer speeds, but the logistics of setting up the actual fibers has stymied companies from rolling out the service. The further that data from fiber optic cables has to go, the less likely it is to be accurately interpreted by a receiver. This means that distance is a limiting factor in designing fiber optic transmission networks. Researchers from the University of California, San Diego, specializing in photonics, have uncovered a way to increase a the maximum power of optical signals travelling through optical fibers. By increasing the power, the distance is effectively increased, too. The researchers sent information over a record-breaking distance of 12,000 km without using any repeaters (electronic regenerators.)

The research is published in the journal, Science. Using a frequency comb, they were able to take an array of frequencies from different channels travelling along a fiber and synchronize them. This limits the "crosstalk" and interference known as the Kerr effect. Without a frequency comb, increasing the power also increased noise, rendering the signals indecipherable over distance.

According to principal author, Nikola Alic,

"Today's fiber optic systems are a little like quicksand. With quicksand, the more you struggle, the faster you sink. With fiber optics, after a certain point, the more power you add to the signal, the more distortion you get, in effect preventing a longer reach. Our approach removes this power limit, which in turn extends how far signals can travel in optical fiber without needing a repeater."

Repeaters are expensive pieces of equipment that need to be placed about every 60 miles along the fiber paths. Without them, the setup cost of fiber optics drops, considerably. So, this discovery could pave the way for faster and cheaper fiber optic networks.

Via: Popular Science