Increasing Optical Fiber Throughput by a Factor of 10
First introduced in the 1970s, fiber optics has provided the world with high speed communication, and is now part of the backbone of the Internet. Since its introduction, the capacity of the technology has increased by an order of magnitude about every four years, through the development of associated technologies. Recently though, that trend has slowed as researchers have hit a bottleneck, but those at EPFL have found a way to greatly improve throughput in one advancement.
A datum traveling through an optical cable is represented by the presence or absence of a light pulse. This is works well for digital data, which is stored as zeroes and ones, but to protect the integrity of the data, each datum must be enough separated from the others that they will not interfere with each other. That means there is a fair amount of empty space in an optical signal. What the EPFL researchers have done is demonstrate an efficient way to reduce the necessary distance between two data. By making the pulses rectangular, so they are equal intensity over a range of frequencies, it is much easier to keep prevent interference, that would otherwise corrupt data.
The idea of creating these 'Nyquist sinc pulses' in optical fibers is not new, but this is the first time it has been achieved with nearly perfect rectangular pulses, and without a complicated infrastructure supporting it. To deploy this solution in an optical fiber network one would just have to replace the transmitters in the system, not the cables, and the new ones would be using technology that has already matured.