World Record-Shattering 402 TB Data Sent In A Second Via Optical Fiber

By attaining an unprecedented 37.6 THz bandwidth and a data transfer rate of 402 terabytes per second (Tb/s) with regular commercially accessible optical fiber, a group of researchers has broken the previous record for data transmission in optical fiber technology. This noteworthy achievement signifies a substantial advancement in the field of telecommunications.

Novel optical gain equalizers, which allowed access to previously untapped wavelength bands in already-existing systems, were the key that made this achievement possible. This technology, according to researchers at Japan’s National Institute of Information and Communications Technology (NICT) Photonic Network Laboratory, will significantly increase optical infrastructures’ capacity for communication, satisfying the rising need for data services.

The increasing demand of optical transmission bandwidth is propelled by the internet growth and data services. As a result, the industry of multiband wavelength division multiplexing (WDM) technology has evolved — an approach using new spectral windows as an adoption to expand optical fiber transmission bandwidth. It offers a low-cost option for sustaining the systems’ lifespan. This can be considered by other players who will not have access to such technologies in the near future.

In order to extend beyond the low-loss regions of standard silica fibers, new amplification strategies that are alternative to Erbium-Doped Fiber Amplifiers (EDFAs) had to be explored. The team went through several options for amplifiers, which include Thulium-Doped Fiber Amplifiers (T-DFAs), Semiconductor Optical Amplifiers (SOAs), and Raman Amplification: they managed to reach a capacity of 256 Tb/s over an almost 20 THz bandwidth. The broader tests with Bismuth-Doped Fiber Amplifiers (B-DFAs) and Raman Amplifiers later achieved up to 320 Tb/s over 27.8 THz bandwidth. In other words, breaking away from the standard limitations was no small feat: it involved thinking out of the box in terms of amplification strategies and resulted in record-breaking data transmission rates.

The NICT study aimed to extend dense wavelength-division multiplexing (DWDM) transmission across all key bands within the low-loss range of standard optical fibers, enabling over 1,500 simultaneous transmission channels across a 37.6 THz (275 nm) optical bandwidth. In collaboration with partners, NICT researchers developed the world’s first O-to-U-band transmission system for DWDM, using commercially available standard optical fiber and custom amplifier technology.

The system transmitted a wide DWDM signal with up to 1,505 channels over 50 km of specialized optical fiber, spanning 275 nm (37.6 THz) from 1,281.2 nm to 1,649.9 nm across O, E, S, C, L, and U bands. High data rates were achieved using dual polarization (DP) quadrature amplitude modulation (QAM) with up to 256 symbols per constellation. The generalized mutual information (GMI) estimated data rate after 50 km was 402 Tb/s, surpassing the previous highest single-mode fiber (SMF) data rate by over 25 percent and increasing the transmission bandwidth by 35 percent.

These results demonstrate the potential of ultra-wideband transmission to significantly boost the information-carrying capacity of both new and existing optical fibers. The substantial rise in data rates for optical transmission systems is expected to facilitate “Beyond 5G” information services. Researchers noted that new wavelength regions would enable higher data-rate transmissions and extend the useful life of existing network systems.

NICT remains committed to advancing research and development in new amplifier technologies, components, and fibers to support novel transmission windows for both short- and long-term applications. The organization will also work to expand the bandwidth transmission range of ultra-high capacity systems and their compatibility with field-deployed fibers.