Data transmission speeds keep accelerating, and the latest achievement is a Scandinavian triumph. Scientists from the Technical University of Denmark and Chalmers University of Technology in Gothenburg, Sweden have successfully transmitted data at 1.8 Pbit/s (petabits per second). It’s a staggering feat, but also one that was achieved with ease and with an ability to spare. And, lest we forget or become jaded, let’s remember that 1Pbit/s is 1 million times faster than 1Gbit/s. Even more impressively, researchers have reached new heights using a single laser and a single optical microprocessor.
The ramifications for data transmission are profound: a data connection operating at 1.8 Mbps is enough to transmit all of the world’s Internet traffic twice in a single second! And that’s just to start. Scientists calculate that a single chip will be able to transmit at 100 Pbit/s – a speed so immense that it is almost beyond comprehension.
In experience, which is reported in full in the prestigious peer-reviewed scientific journal Nature Photonics, teams from the universities used a single custom-designed optical chip capable of harnessing light pumped from a single infrared laser.
This light was split into 223 totally separate streams, each corresponding to different frequencies in the electromagnetic spectrum. The frequencies are therefore separate and cannot interfere with each other (think of the teeth of a comb and you’ll get the idea), and each frequency (or color of light) can carry separate streams of data that can travel at very high speed and with great efficiency before being recombined on reception and sent over an optical fiber. The volume of data transmitted by this means is enormous.
The single laser solution used in the experiment to deliver a data rate of 1.8 Pbit/s would have required more than 1,000 of the best and most advanced lasers currently available for commercial purposes to achieve the same results. Dr. Victor Torres Company, who is a professor at Chalmers University of Technology, leads the research team that developed and manufactured the new microprocessor. He said: “The special thing about this chip is that it produces a frequency comb with ideal characteristics for fiber optic communication. [in that] it has high optical power and covers a wide bandwidth in the spectral region which is attractive for advanced optical communications.”
It was by chance that the tests revealed that the new chip can handle and sustain traffic loads of 100Pbit/s. Dr Company explained: “In fact, some of the characteristic parameters were obtained by coincidence and not by design” and were therefore not specifically defined for the experiment. “However, thanks to the team’s efforts, we can reverse engineer the process and obtain high reproducibility microcombs for target applications in telecommunications,” he added.
While the successful demonstration of 1.8 Mbps data transmission is impressive in itself, it’s the scaling potential that makes the technology so important. Professor Leif Oxenløwe, Director of the Center of Excellence for Silicon Photonics for Optical Communications at the Technical University of Denmark (DTU), said: “Our calculations show that with the single chip made by the University of Chalmers technology and a single laser, we be able to transmit up to 100Pbit/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 multiple 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 use for spectrally efficient data transmission.
Red lasers for greener telecoms
The Scandinavian research also has major implications for sustainability, as it is expected to result in the replacement of most lasers already deployed in communications infrastructure in data centers, internet nodes and local telecom exchanges, all of which consume energy. enormous amounts of energy and generate enormous amounts of heat. As Professor Oxenløwe comments, we now have “the opportunity to contribute to the realization of an Internet that leaves a smaller climate footprint”.
Additional Note: Infrared radiation, which is electromagnetic radiation with wavelengths longer than light visible to humans, was discovered in 1800 by Friedrich Herschel while experimenting with measuring the temperature of different colors of sunlight and separated them by passing them through a prism. He put thermometers in the individual color ranges and noticed that the highest temperatures were always at the red end of the spectrum. Thus, he concluded that the solar spectrum has an invisible continuum beyond that of visible red light. Scientists then divided infrared into five subdivisions and named the categories near infrared, short-wavelength infrared, mid-wavelength infrared, long-wavelength infrared, and far infrared.
For most people, the closest contact they have with infrared in the home context is when changing channels on a television. The ubiquitous channel changer uses light waves that are just beyond, but very close to, the visible spectrum of light. Interestingly, research has shown that some people are able to perceive or detect infrared at 1060 nm, but “see” it as faint green light.
The human eye did not evolve to see infrared but, if we could see it, we couldn’t see blue or indigo and therefore almost everything we would observe would be yellow and orange with a tint of green . Think permanent Halloween (as is very appropriate, given today’s date) and a visible landscape with trees that look permanently autumnal and most things in the colors of pumpkins, butternut squash, carrots and ginger cats – whether they are actually ginger cats or not.
