A tiny experimental optical chip can support downloads of 1,000 movies in a split second

An optical chip the size of a fingernail has enabled Australian researchers to set new optical data rate records on the country’s National Broadband Network (NBN).

The raw data rate of 44.2Tbps over conventional optical cable is about three times the data rate for the entire NBN network and about 100 times the speed of any single device currently used on the network, the researchers say.

While the technology is meant for metro-area networks and data centers, those bit rates would support downloads of 1,000 movies in less than a second.

The chip, known as a microcomb, splits the light of a laser into different frequencies that can be used as different paths or lines to carry data. The ability to supply those wavelengths with a single compact chip can replace many parallel lasers, reducing the cost and complexity of optical links, according to an article about the project in Nature Communications.

The research to develop the chip and test it were conducted by scientists at Monash University, RMIT Universitiy and Swinburne University, all in Australia, along with Institut National de la Recherche Scientifique in Canada, CIOPM Xi’an, and CityU Hong Kong. The tests were run over a 77km optical fiber loop around Melbourne, Australia.

“This shows that the optical fibers we have in the ground today can handle huge capacity growth, simply by changing what we plug into those fibers,” writes Bill Corcoran, a lecturer at Monash University, and one of the scientists developing the project, in The Conversation.

Micro-combs use a single laser with a temperature-controlled microprocessor and a small ring about a millimeter across known as an optical resonator. Over a hundred distinct lines, can be created with the setup, he says and 80 of the 100 available lines were used in the experiment.

Corcoran says the spread of coronavirus has increased usage of the internet, citing the request of the European Union earlier in the pandemic for streaming services to cut back on the bandwidth they use as an indication that global bandwidth is under strain.

In its Nature Communications paper, the development group said there has been a shift in focus over the past 10 years from creating long-haul optical networks to increasing bandwidth on metro and data center links, and their work can help provide that bandwidth efficiently over existing fiber.

“All of this is driving the need for increasingly compact, low-cost and energy-efficient solutions, with photonic integrated circuits emerging as the most viable approach,” the paper says.