Optical fiber communication is the backbone of the Internet. As essential core technologies are approaching their limits of size, speed, and energy efficiency, there is a need for new technologies that offer further scaling of data transmission capacity.
Now, an international group of researchers from the Technical University of Denmark (DTU) and the Chalmers University of Technology in Gothenburg, Sweden, have achieved dizzying data transmission speeds and are the first in the world to transmit more than 1 petabit per second (Pbit/s) using only a single laser and a single optical chip. Their data transmission method uses significantly less power and can help reduce the Internet’s climate footprint.
In the experiment, the team succeeded in transmitting data at a blistering rate of 1.84 Pbit/s, almost twice the global internet traffic per second – 1 petabit is a million gigabits. It’s more than 20 times faster than ESnet6, the upcoming upgrade to the scientific network.
The demonstration was only carried by the light from one optical source. The light source is a custom-designed optical chip that can use the light from a single infrared laser to create a rainbow spectrum of many frequencies or colors. Thus, the one frequency of a single laser can be multiplied into hundreds of frequencies (colors) in a single chip.
All the colors are fixed at a specific frequency distance from each other – just like the teeth on a comb – and hence called a frequency comb. Each color can then be isolated and used to imprint data. The frequencies can then be reassembled and sent over optical fiber, thus transmitting data.
Researchers used this setup to transmit data at 1.84 Pbit/s over a 37-core, 7.9-km-long fiber using 223 wavelength channels derived from a single microcomb ring resonator. This data transmission speed greatly exceeds the previous record of 1.02 Pbit/s, which was set in May this year.
In addition, the researchers created a computational model to theoretically examine the fundamental potential for data transmission with a single chip identical to the one used in the experiment. The researchers claim a single, chip-scale light source could eventually be able to support 100 Pbit/s in massively parallel space-and-wavelength multiplexed data transmission systems.
“Our calculations show that – with the single chip made by the Chalmers University of Technology and a single laser – we will be able to transmit up to 100 Pbit/s,” said Professor Leif Katsuo Oxenløwe, Head of the Centre of Excellence for Silicon Photonics for Optical Communications (SPOC) at DTU. “The reason for this is that our solution is scalable – both in terms of creating many frequencies and in terms of splitting the frequency comb into many spatial copies and then optically amplifying them and using them as parallel sources with which we can transmit data. Although the comb copies must be amplified, we do not lose the qualities of the comb, which we utilize for spectrally efficient data transmission.”
These new findings could mark a shift in the design of future communication systems, targeting device-efficient transmitters and receivers.
- A. A. Jørgensen, D. Kong, M. R. Henriksen, F. Klejs, Z. Ye, Ò. B. Helgason, H. E. Hansen, H. Hu, M. Yankov, S. Forchhammer, P. Andrekson, A. Larsson, M. Karlsson, J. Schröder, Y. Sasaki, K. Aikawa, J. W. Thomsen, T. Morioka, M. Galili, V. Torres-Company and L. K. Oxenløwe. Petabit-per-second data transmission using a chip-scale microcomb ring resonator source. Nature Photonics (2022); DOI: 10.1038/s41566-022-01082-z