The world's fastest data transmission speed record has been broken yet again, paving the road for increasingly instantaneous transmission of the world's entire knowledge repository. The team who achieved this feat are researchers from Technical University of Denmark (DTU) and Chalmers University of Technology in Gothenburg, Sweden. Their novel technique leverages a single laser and a single, custom-designed optical chip enabling throughputs to the tune of 1.8 Pbit/s (Petabits per second) — double today's global internet traffic.
For scale, the same data transmission record had been previously broken back in August 2020 with a then-astonishing 178 Tbit/s (Terabits per second) — enough to download Netflix's then-existing catalog in less time than you could count a single Mississippi. But that speed is only around 10% of today's maximum throughput announcement, meaning that in less than three years we've improved the technology tenfold.
Some of the secret sauce behind the record hails from the proprietary optical chip, which can take the input from a single infrared laser to create a spectrum of many colors. Each color represents a frequency that's not unlike the teeth of a comb, perfectly and equally distinguishable from one another (this is exactly the process through which we distinguish colors, by detecting the different frequencies of light materials reflect towards us). And since these multiple frequencies are perfectly distinguishable from one another, with a set separate distance between each, that information can be transmitted across each of these frequencies (or channels). The more colors/frequencies/channels, the more data can be sent, which led to the establishment of the new 1.8 Pbit/s transmission speed world record.
Today's optical technology would require around 1,000 different lasers to produce the same amount of wavelengths capable of transmitting all of this information. That in itself is a problem; each additional laser increases energy consumption, multiplies the number of failure points, and makes the setup harder to manage.
Victor Torres Company, professor at Chalmers University of Technology and head of the research group that has developed and manufactured the chip, explained something of the team's work:
“What is special about this chip is that it produces a frequency comb with ideal characteristics for fiber-optical communications – it has high optical power and covers a broad bandwidth within the spectral region that is interesting for advanced optical communications,” he said.
Interestingly, like many other scientific "missteps", the initial design purpose wasn't to break the world's transmission throughput record:
“In fact, some of the characteristic parameters were achieved by coincidence and not by design,” Victor Torres Company added. “However, with efforts in my team, we are now capable to reverse engineer the process and achieve with high reproducibility microcombs for target applications in telecommunications.”
The research has practical applications that should be scaled out of the lab, as well - the idea isn't for this technology to grab a headline and become abandoned to the corridors of vaporware. According to professor Leif Katsuo Oxenløwe, Head of the Centre of Excellence for Silicon Photonics for Optical Communications (SPOC) at DTU, the technology shows tremendous potential for being scaled up:
“Our calculations show that—with the single chip made by Chalmers University of Technology, and a single laser—we will be able to transmit up to 100 Pbit/s. 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.”
It's mind-blowing to think about so much information that it could strain a 100 Pbit/s connection — around 100 times the traffic flow of today's internet. But build the highways, as they say, and the traffic will come.
