Researchers from the Network System Research Institute of the National Institute of Information and Communications Technology (NICT, Japan) have achieved the world's first transmission exceeding 1 petabit per second (125,000 Gbps) in a single-core multi-mode optical fiber. This beats the current record transmission in a multi-mode fiber by 2.5 times.
15 fiber modes
"To date, transmission experiments in optical fibers supporting large number of modes were limited to small optical bandwidths. In this study, we demonstrated the possibility of combining highly spectral efficient wideband optical transmission with an optical fiber guiding 15 fiber modes that had a cladding diameter in agreement with the current industry standard of 0.125 mm," wrote the researchers in a statement.
To conduct their experiment, the researchers developed a wideband transceiver subsystem to transmit and receive several hundred highly spectral efficient WDM (Wavelength Division Multiplexing) channels of high signal quality. It was this transmission system that made use of a multi-mode fiber that demonstrated the record-breaking transmission speed.
"When increasing the number of modes in a multi-mode fiber transmission system, the computational complexity of the required MIMO (Multi-Input Multi-Output) digital signal processing increases. However, the used transmission fiber had a small modal delay, simplifying the MIMO complexity and maintained this low modal delay over a large optical bandwidth. As a result, we could demonstrate the transmission of 382 wavelength channels, each modulated with 64-QAM signals," the researchers wrote.
High capacity systems
The success of this experiment is expected to advance high-capacity multimode transmission technology for future high capacity optical transmission systems. Now, the researchers have plans to extend the distance of large-capacity multi-mode transmission and integrate it with multi-core technology to establish the foundation of optical transmission technology with increased capacity.
The paper on this experiment was published at the 46th European Conference on Optical Communication, one of the largest international conferences on optical fiber communication.