Currently, the fastest commercially available fiber optic line tops out at 100 Gbps. That's super fast, sure, but isn't nearly a wide enough pipeline for our increasingly interconnected systems. That's why this new, multi-modal, fiber line is so exciting—it can pack 2,550 times as much data into the same glass strand.


That's right, a 255 terabit-per-second throughput. That's enough to transfer a 1 GB file in 31 microseconds (.003 sec) or move the entire contents of a 1TB drive in three tenths of a second. In fact, 255 Tbps is roughly the equivalent to the peak load on the Internet's transatlantic backbone. This single strand could, quite literally, replace the existing plethora of single-mode sub-sea cables.

The record-breaking technology was developed by an international team of researchers from Eindhoven University of Technology in the Netherlands and the and University of Central Florida here in the US. They were able to achieve this impressive feat thanks to an existing (but prohibitively expensive) technology known as multi-mode fiber. The existing transatlantic cables are all made of single-mode fiber—that is, each line can only carry data from a single source laser—but this new multi-mode fiber contains seven separate "cores" and can therefore each multi-core fiber carry up to seven distinct signals simultaneously.


The team also employed some tricky data transmission manipulation to pack the line. They first leveraged a spacial multiplexing (SM) technique—where individual encoded data signals from multiple sources are transmitted in parallel—to reach a speed of 5.1 terabits per carrier. They also utilized wavelength division multiplexing (WDM)—which works similarly to SM but separates and transmits individual data streams in varying wavelengths of light—to get 50 separate signals moving down the kilometer-long line simultaneously.

In short: it's a mix of hardware and software innovation.

As the team's research abstract in the October issue of Nature explains:


Single-mode fibres with low loss and a large transmission bandwidth are a key enabler for long-haul high-speed optical communication and form the backbone of our information-driven society. However, we are on the verge of reaching the fundamental limit of single-mode fibre transmission capacity. Therefore, a new means to increase the transmission capacity of optical fibre is essential to avoid a capacity crunch. Here, by employing few-mode multicore fibre, compact three-dimensional waveguide multiplexers and energy-efficient frequency-domain multiple-input multiple-output equalization, we demonstrate the viability of spatial multiplexing to reach a data rate of 5.1 Tbit s−1 carrier−1 (net 4 Tbit s−1 carrier−1) on a single wavelength over a single fibre. Furthermore, by combining this approach with wavelength division multiplexing with 50 wavelength carriers on a dense 50 GHz grid, a gross transmission throughput of 255 Tbit s−1 (net 200 Tbit s−1) over a 1 km fibre link is achieved.

Obviously, this technology is far from being field-ready. Not only would replacing the existing single-mode infrastructure with these more-expensive multi-mode lines be expensive and difficult; it'd require entirely new routing hardware as well. It'd be like replacing every two-lane highway in America with eight-lane raised freeways. It's totally possible, just not economically feasible. But, given how fast the Internet is currently growing, it won't be long until we need this technology. [Nature via Extremetech]



Image: Sukharevskyy Dmytro (nevodka)