Researchers from the Technical University of Denmark (DTU) and the Chalmers University of Technology in Gothenburg, Sweden have achieved data rates over 1Pbit/s using a single laser and a single optical chip.
The international team succeeded in transmitting 1.84Pbit/s using one optical source over a 37-core, 7.9-km-long fibre. The light source is a custom-designed frequency comb ring resonator that generates 223 wavelength channels. An equivalent system today would need over 1000 lasers, marking a significant reduction in the size and power consumption of transmission systems for the Internet.
“We also present a theoretical analysis that indicates that a single, chip-scale light source should be able to support 100Pbit/s in massively parallel space-and-wavelength multiplexed data transmission systems. Our findings could mark a shift in the design of future communication systems, targeting device-efficient transmitters and receivers,” say the researchers.
“What is special about this chip is that it produces a frequency comb with ideal characteristics for fibre-optical communications – it has high optical power and covers a broad bandwidth within the spectral region that is interesting for advanced optical communications,” said Victor Torres-Company, professor at the Chalmers University of Technology.
“In fact, some of the characteristic parameters were achieved by coincidence and not by design,” he said. “However, with efforts in my team, we are now capable to reverse engineering the process and achieve with high reproducibility micro combs for target applications in telecommunications.”
“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 100Pbit/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.”
“In other words, our solution provides the potential for replacing hundreds of thousands of lasers located at Internet hubs and data centres, all of which guzzle power and generate heat. We have an opportunity to contribute to achieving an Internet that leaves a smaller climate footprint,” says Oxenløwe.
“All over the world, work is being done to integrate the laser source in the optical chip, and we’re working on that as well. The more components we can integrate in the chip, the more efficient the whole transmitter will be. I.e. laser, comb-creating chip, data modulators, and any amplifier elements. It will be an extremely efficient optical transmitter of data signals,” he said.
