Engineers have broken the data rate record over fiber, reaching 319 terabits per second.
The world internet speed record was broken when Japanese engineers demonstrated data transfer rates of 319 terabits per second (Tb/s) over fiber optic cables. The record was set over a distance of over 3,000 km using the existing cable infrastructure.
It’s hard to even imagine how high this transfer rate is. It almost doubled the previous record of 178 TB/s set less than a year ago. NASA is getting by with “only” 400Gbps, and that’s absolutely space-saving compared to the speeds currently available to consumers. The fastest home internet connections peak at 10Gbps in parts of Japan, New Zealand and the US, while the vast majority of subscribers in other parts of the world are unlikely to exceed 1Gbps.
The breakthrough was achieved using the existing fiber optic infrastructure with the addition of more advanced technologies. First, it used four “cores” — glass tubes inside the fibers through which data is transmitted — rather than a standard single core. The signals were split into multiple wavelengths transmitted simultaneously using a wavelength division multiplexing (WDM) technique. To transmit more data, a rarely used third “band” is added, and the distance is increased thanks to optical amplification technology.
Diagram of the new NICT transmission system:
The system starts with a comb laser that generates 552 channels at different wavelengths. This light then goes through dual polarization modulation, delaying some wavelengths to create different signal sequences. Each of these signal sequences is then fed into one of the four strands of the optical fiber.
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The data travels approximately 70 km along the fiber before meeting optical amplifiers to keep the signal strong over long distances. Here it goes through two new types of fiber amplifiers, one doped with erbium and the other with thulium, before going through a common process called Raman amplification. The signal sequences are then sent to the next segment of the optical fiber. Repeating this process allowed the team to transmit data over an impressive distance of 3,001 kilometers.
It is important to note that a four-core optical fiber has exactly the same diameter as a standard single-core fiber, taking into account the protective sheath. This means that this technology should be relatively easy to implement into existing fiber optic infrastructure.
A paper describing this achievement was presented at the International Fiber Optic Conference last month.