A study presented at the International Conference on Fiber Optic Communication in June has revealed that Japanese engineers recently broke the world record for the highest internet speed, achieving a data transfer speed of 319 terabits per second (Tb/s). The new record was set on a fibre cable that stretched over 3,000 kilometres, and it appears to be compatible with the current cable infrastructure.
The transmission speed is nearly twice as fast as the previous record of 178 Tb/s, which was set less than a year ago and seven times faster than the previous record of 44.2 Tb/s set by an experimental photonic chip.
The American space agency NASA itself uses a pretty basic speed of 400 gigabits per second (Gb/s). However, the new record rises high above the current speed available to the customers—in regions of Japan, New Zealand and the United States, the fastest home internet connections reach 10 Gb/s.
This new achievement was made possible by combining existing fibre optic infrastructure with more advanced technologies. Instead of the traditional standard core, the research team used four “cores,” which are glass tubes placed in the fibres that transmit data. Using a technique called wavelength division multiplexing (WDM), the signals are then separated into numerous wavelengths and broadcast at the same time. To carry more data, a rarely used third “band” is added, and the distance is increased using various optical amplification technologies.
The new system starts the transmission process with a 552-channel cam laser fired at various wavelengths. Dual polarisation modulation is then applied to this light, delaying some wavelengths to create distinct signal sequences, and after that, each of these signal sequences is fed into one of the optical fibre’s four cores. Data is transferred via 70 kilometres of optical fibre until it reaches optical amplifiers, which boost the signal on its long journey. The signal passes through two new types of fibre amplifiers, one doped in thulium and the other in erbium, before continuing on its path in the traditional Raman amplification process.
According to Japan’s National Institute of Information and Communications Technology (NICT), the signal patterns are then guided into a fresh piece of optical fibre, and the team of Japanese researchers was able to send data over a distance of 3,001 kilometres by repeating this process.
After the protective cladding is taken into account, the four-core optical fibre has the same diameter as a typical single-core fibre. It means that the new method will be considerably easier to integrate into existing infrastructure than prior technical overhauls of social information systems.
However, not only have Japanese scientists blown the 2020 record out of the water, but they have done so with a novel technical solution that can be easily integrated into the modern fibre-optic infrastructure.
Japan’s primary national research institute for information and communications NICT stated that it would “continue to develop wide-band, long-distance transmission systems and explore how to further increase the transmission capacity of low-core-count multi-core fibres and other novel SDM fibres. Further, we will work to extend the transmission range to trans-oceanic distances”.