Achievement: Record Single-Channel Data Rate Transmission over the Standard Optical Fiber

 Hello everybody,

It is a great pleasure to share that recently our work has received much appreciation. We set a new world record on the single-channel data rate of the standard optical fiber. In this blog, I share our work in brief.

Our work is about mitigating the distortions and thus, increasing the transmission capacity of fiber-optic communication systems. These systems carry 99% of today’s internet traffic and are under pressure due to an exponential rise in bandwidth-hungry services such as video conferencing, HD video streaming and online gaming. In order to increase the data-carrying capacity of networks while keeping a lower cost, researchers and industries around the world are working hard to achieve higher capacity per fiber.

The innovation is usually applied at transmitters and receivers where information bits are encoded into higher modulation format symbols (i.e. multiple amplitudes and phase levels of light), and then, those symbols are transmitted at rates beyond 100 billion symbols/second. Such systems that are already operating at their limits, distortions from hardware components become critical.

Recently, we studied such a research experimental setup that operates at 128 billion symbols/second and can use 16 amplitude levels of light to modulate information. We proposed a novel NN based nonlinear digital pre-distortion (DPD) filter that compensates the transmitter distortions and improves signal integrity. By incorporating the responses of actual transmitter hardware in our numerical model and through several numerical simulations, we tailored the architecture of the proposed NN-DPD. Furthermore, with our insights about the experimental system, the proposed DPD was improved to achieve better performances and to reduce training efforts.

An example schematic showing how with application novel neural network-based digital pre-distortion at transmitter improves the integrity of the received signal.

The NN-based filter was tested on the state-of-the-art experiment setup for various degrees of transmitter distortions at Nokia Bell Labs, Stuttgart. With the application of our proposed NN-DPD at the transmitter, we compensated the transmitter distortions and achieved a record highest net data rate of 1.61 Terabits/second over a single wavelength. This achievement was presented at ECOC 2020 as a highly scored paper and recognized in Nokia Bell Labs with Bell Labs Summer Intern Award for Outstanding Innovation.

I would like to thank the team (Dr. Aref. Dr. Buchali, Dr. Chagnon from Nokia Bell Labs, Stuttgart, and Dr. Wahls from TU Delft) for this great collaborative research.