It is only a matter of time before the data pipes that connect us to our social networks, work e-mail, and the Internet's vast repository of useful and useless information fill up. It could be five years, it could be 15, but our boundless appetite for bandwidth-consuming apps, streaming video, and other data will soon clog up current fiber optic cables.
Since the 1990s, scientists have been trying to develop ways to increase capacity. Since data is encoded in pulses of light that travel through fiber optic cables, the first obvious approach was to use different kinds of light. For years, scientists have used different colors of light to transmit information, essentially creating new channels by using different colors. But as they have crammed more and more colors of light into fiber optic cables, they have found they are rubbing up against a physical threshold — either running out of colors or foiled by the way that different streams of light interact with each other, providing a scrambled output at the end.
“The road map, when we look at all the demand for bandwidth, essentially says at some point we have to get to 1 million terabits per second — in the next 10 to 20 years,” said Siddharth Ramachandran, an engineering professor at Boston University, who described a new approach to increasing capacity in the journal Science.
In a collaboration with a Danish fiber optic company called OFS-Fitel, scientists built a whole new type of fiber that could carry light in separate modes, each of which would travel a separate path that would mean they could not get jumbled up.
The scientists demonstrated that they could create four channels carrying separate modes of light in a specially-designed fiber. They showed that at least two of those channels could carry 10 colors of light, creating data transmission rates of 1.6 terabits per second.