Microcombs could be key in meeting bandwidth demands for artificial intelligence and data centres

A newly-published paper from Swinburne University of Technology shows how a kind of “optical ruler”, or frequency comb, can greatly increase bandwidth in today’s data-saturated world. Integrated optical frequency comb sources, or microcombs, have driven major advances in spectroscopy, metrology and more.

Their potential in data transmission is especially promising, exceeding speeds of one petabit per second – 10 million times faster than a 100Mbit/s NBN connection.

Distinguished Professor David Moss, Director of the Optical Sciences Centre at Swinburne University of Technology, and Deputy Director of the Australian Research Council Centre of Excellence, the Centre for Optical Microcombs for Breakthrough Science (COMBS), has just published a key review paper – “Optical microcombs for ultrahigh-bandwidth communications” – in the prestigious journal Nature Photonics.  

A laboratory-based optical frequency comb earned the 2005 Nobel Prize in physics. The technology has enabled breakthroughs in microwave photonics, frequency synthesis, optical ranging, quantum sources, and more, but one of its greatest successes has been in optical communications.

“The world’s optical fibre communications network forms the backbone of the global internet. Worldwide traffic is hundreds of terabits of data every second and growing exponentially at over 25 per cent per annum,” says Professor Moss.

While optics has greatly underpinned this, the exponentially increasing demand for data – being driven in large part by data centres and artificial intelligence – has created huge bottlenecks that will need radical technological innovations to overcome. 

Integrated microcombs can generate hundreds of wavelengths coherently on a single chip and have now achieved levels of performance, reliability, stability and coherence allowing them to serve as integrated sources for ultrahigh capacity data transmission. 

This paper reviews this progress and covers the state of this field, discussing promising new types of microcombs, new technologies such as space division multiplexing, and which markets microcombs may have the biggest initial impact. 

“These devices have already enabled research demonstrations of communications at unprecedentedly ultra-high bandwidths and with greatly reduced energy consumption in an ultra-small integrated footprint. They could very well be a game changer in meeting growing bandwidth demands – particularly for data centres – and reducing energy consumption to perform well beyond existing technology,” says Professor Moss.

The review was co-authored by Associate Professor Bill Corcoran at Monash University, Professor Arnan Mitchell at RMIT University in Melbourne, Professor Roberto Morandotti at the INRS-EMT in Canada, and Professor Leif Oxenlowe at the Danish Technical University in Copenhagen, Denmark.