The team developed a new way to generate extremely stable light signals using microscopic, ring-shaped devices called microresonators. These signals form what scientists call optical frequency combs, sometimes described as optical rulers because they produce a series of evenly spaced colors of light that can be used to measure light with extraordinary precision.
The researchers also demonstrated a new type of light pulse called a "hyperparametric soliton." This stable pulse is key to the significant advance of this work, as it allows the comb signals to be produced in different colors of light from the laser powering the device.
This makes the technology useful for high-speed optical communications, which play a critical role in data transfer (in data centers).
The researchers demonstrated this in a wavelength region used for high-speed data links within large data centers—an area of growing importance as data demand continues to increase with the expansion of AI computing infrastructure.
What is the potential impact of this research?
Data centers require enormous amounts of energy to perform the myriad tasks we demand of them, and those demands are increasing rapidly, driven, in part, by our ever-growing use of AI. According to the Central Statistics Office of Ireland, data centers accounted for 22% of total electricity consumption in 2024—more than all urban households (18%) combined. And their electricity consumption increased by 10% year-on-year.
Given the upward trajectory of our reliance on data centers and their energy needs, any technological innovation that improves efficiency can have a real impact on reducing electricity consumption and contribute to achieving ambitious carbon emissions targets.
Professor John Donegan, Chair of Physics at Trinity College Dublin and a CONNECT Research Ireland Centre for Future Networks Fellow, said: "We are very excited to have created a new type of optical source that will be of great interest to those working in optical communications and high-precision optical measurements."
“In collaboration with a leading optics theorist at the University of Bath and the world-leading microresonator manufacturing group in Switzerland, my group has been able to demonstrate a new type of comb source.”
“Our work also benefits from collaboration with Pilot Photonics, a DCU spin-off company that develops high-precision lasers and comb sources for optical communications. We anticipate that this is just the beginning of this work and that it will develop significantly in the coming years.”
How could this work lead to the next generation of optical networks?
“Modern fiber optic networks send large amounts of data by transmitting many different colors of light through a single optical fiber, a technique known as wavelength division multiplexing (WDM),” added Professor Donegan.
“But optical frequency combs can generate many of these colors from a single light source, potentially replacing separate laser arrays. By simplifying system design while simultaneously improving efficiency and stability, comb-based technologies could become critical components for future data center networks and high-capacity internet infrastructure.”
This research was supported by Research Ireland, the UK Engineering and Physical Sciences Research Council, the CONNECT Centre, the Royal Society, and the Zhejiang Innovation and Entrepreneurship Leading Teams.
