Researchers at Trinity College Dublin have made significant strides in developing a novel light-based technology on a compact chip, aimed at improving the efficiency and speed of data centres that underpin cloud computing, artificial intelligence, and global Internet services.
This groundbreaking research has been published in the esteemed journal Nature Communications, showcasing collaboration with experts from the University of Bath and the Swiss Federal Institute of Technology Lausanne (EPFL).
The team has introduced a new method for generating exceptionally stable light signals using microscopic ring-shaped devices known as ‘microresonators’. These signals create what are referred to as optical frequency combs, which are sometimes likened to ‘optical rulers’ due to their ability to produce a series of uniformly spaced colours of light, allowing for precise measurements.
Additionally, the researchers have successfully demonstrated a novel type of light pulse termed a ‘hyperparametric soliton’. This stable pulse is crucial for the advancements achieved in this study, enabling the production of comb signals at various colours of light derived from the powering laser.
Such technology proves beneficial for high-speed optical communications, a vital component for data transfer. The research highlights its application in wavelengths essential for high-speed data links within expansive data centres, which are increasingly significant as the demand for data surges alongside the expansion of AI computing infrastructure.
Data centres consume substantial energy to manage the vast array of tasks required of them, with energy demands rapidly escalating, partly due to the rising utilisation of AI. According to the Central Statistics Office, data centres accounted for 22% of total electricity consumption in 2024, surpassing the combined electricity use of all urban households (18%). Notably, their electricity consumption increased by 10% from the previous year.
Professor John Donegan, a Professor of Physics at Trinity College Dublin and a funded investigator at the Connect Research Ireland Centre for Future Networks, expressed enthusiasm about this development, stating: ‘We are very excited to have generated a new type of optical source that will be of strong interest to those working in optical communications and high-precision optical measurements. Collaborating with distinguished optical theorists at the University of Bath and a leading microresonator fabrication group in Switzerland, my team has successfully demonstrated a new type of optical comb source.’
He further noted the collaboration with Pilot Photonics, a spin-out from Dublin City University, which is developing high-precision laser and comb sources for optical communications. Professor Donegan anticipates that this research is merely the beginning of a promising trajectory in this field.
Modern fibre-optic networks transmit vast amounts of data by sending multiple colours of light through a single optical fibre, a method known as wavelength-division multiplexing (WDM). Optical frequency combs have the potential to generate many of these colours from a single light source, which could replace the need for arrays of individual lasers. This simplification of system design, combined with enhanced efficiency and stability, positions comb-based technologies as crucial components for future data centre networks and high-capacity internet infrastructure.
The research has received support from Research Ireland, the UK Engineering and Physical Sciences Research Council, the Connect Centre, the Royal Society, and the Leading Innovation and Entrepreneurship Teams of Zhejiang.