Scientists Set New Data Transmission World Record Using Single Light Source

Posted  by GoPhotonics

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An international group of researchers from the Technical University of Denmark (DTU) and the Chalmers University of Technology in Gothenburg, Sweden have set a world record by achieving a data transmission speed of 1.8 petabits per second. They 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. The employed data transmission method uses significantly less power and can help reduce the Internet’s climate footprint.

1 petabit corresponds to 1 million gigabits.

In the experiment, the researchers succeeded in transmitting 1.8 Pbit/s, which corresponds to twice the total global Internet traffic. And only carried by the light from one optical source. The light source is a custom-designed optical chip, which can use the light from a single infrared laser to create a rainbow spectrum of many colors, i.e. many frequencies. Thus, the one frequency (color) 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 - which is why it is called a frequency comb. Each color (or frequency) can then be isolated and used to imprint data. The frequencies can then be reassembled and sent over an optical fiber, thus transmitting data. Even a huge volume of data, as the researchers have discovered.

One single laser can replace thousands

The experimental demonstration showed that a single chip could easily carry 1.8 Pbit/s, which—with contemporary state-of-the-art commercial equipment—would otherwise require more than 1,000 lasers.

“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,” says Victor Torres Company, the professor at the Chalmers University of Technology, and the head of the research group that has developed and manufactured the chip.

Interestingly enough, the chip was not optimized for this particular application.

“In fact, some of the characteristic parameters were achieved by coincidence and not by design,” says Victor Torres Company. “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.”

Enormous potential for scaling

In addition, the researchers created a computational model to examine theoretically the fundamental potential for data transmission with a single chip identical to the one used in the experiment. The calculations showed enormous potential for scaling up the solution.

“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." says 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.” 

Reduces Internet power consumption

The researchers’ solution bodes well for the future power consumption of the Internet.

“In other words, our solution provides a potential for replacing hundreds of thousands of the 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 Leif Katsuo Oxenløwe.

Even though the researchers have broken the petabit barrier for a single laser source and a single chip in their demonstration, there is still some development work ahead before the solution can be implemented in our current communication systems, according to Leif Katsuo 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," says Leif Katsuo Oxenløwe. "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.” 

Click here to read the report titled "Petabit-per-second data transmission using a chip-scale microcomb ring resonator source."