Data transmission demands are expanding all over the world, and many experiments in optical transmission systems have been conducted in the last 10 years. Recently, Japan’s National Institute of Information and Communications Technology (NICT) has achieved a new record for data transfer.
It’s tough to exemplify just how fast the transmission is. It’s nearly twice as fast as the previous record, which was set less than a year ago at 178 Tb/s. NASA manages to somehow get just 400 Gb/s. In Japan, New Zealand, and the United States, the fastest home internet connections reach 10 gigabits per second.
George Rademacher (NICT, Japan), Nicolas K. Fontaine (NOKIA Bell Labs, USA), and Pierre Sillard (Prysimian Group, USA) led a team of researchers who achieved the world’s first transmission exceeding 1 petabit per second in a single core multimode optical fibre.
The study revealed the feasibility of combining extremely efficient broadband optical transmission spectrum with a fibre optic cable (15 modes) with a jacket diameter of 0.125nm, which is congruent to the current industry standard. The transmission was successfully completed across a distance of up to 23 kilometres.
The core diameter of the transmission optical fibre shown below is 0.028mm, with a typical jacket diameter of 0.125mm. The optical fibre is designed to allow 15 fibre mods to transmit while minimising the difference in transmission latency between all 15 mods. In 10-mode multimode fibre, the current record data rate is 0.4 petabits per second.
During the test at NICT, the Prismian transmission fibre and modal multiplexers from Bell Labs were used. A wideband transmit/receive subsystem was developed at Japan’s NICT, and it is being used to send and receive hundreds of highly spectral WDM channels with excellent signal quality.
“The transmission fiber was 23km long and had a graded-index design. It was based on existing multimode fibre designs that were optimised for broadband operation and had a jacket diameter of 0.125mm and a sheath diameter of 0.245mm, both of which conform to the current industry standard.”
However, the computing complexity required for the MIMO signal increases as the number of mods in a multimode fibre transmission system increases. In one experiment, a transmission fibre with short modal delays was used. MIMO complexity was minimised while modal delays were kept low across a wide optical bandwidth. All of this allowed 382 channels to be transmitted, each modulated by a 64-QAM signal.
After forward error correction, the data rates for all 382 WDM channels are shown in the graph above. When all wavelength channels’ data rates are combined together, the total data rate is 1.01 petabits per second.