An international team led by researchers at Heriot-Watt University in the UK has announced the successful real-world test of its photonic chip, which uses tiny glass channels to link multiple telescopes into a single, more powerful tool during on-sky observations at the CHARA Array in California.
The team behind the novel achievement, which included researchers from Cologne and Potsdam Universities in Germany and Georgia State University, where the CHARA array is housed, said demonstrating its custom-made photonic chip during actual astronomical observations marks an important step for the emerging generation of “astronomical technology.”
Photonic Chip Replaces Current Bulkier Light Combining Technologies
According to a statement announcing the photonic chip test, the CHARA array is among the world’s preeminent high-resolution astronomy facilities. The team said one primary reason is that the six-telescope facility can be linked together to study celestial objects in “extraordinary detail.”
“Astronomers can achieve much sharper views of the universe by combining observations from several telescopes at the same time,” explained Professor Robert Thompson from Heriot-Watt University’s Institute of Photonics and Quantum Sciences, who developed the chip with the University’s Dr. Aurélien Benoît. “This allows the telescopes to work together as though they were one much larger telescope.”
Still, collecting light from six different telescopes and combining them into a single image requires an unusually high level of optical precision. Professor Thompson said that the current process for combining light from different telescopes “requires bulky instruments with complex arrangements of mirrors and lenses.”
“We have shown that much of that work can instead be carried out by a glass chip only a couple of centimetres in size,” the Professor explained.
CHARIOT Successfully Combined Light from Six Telescopes
To control light with extreme precision, the researchers used an ultrafast laser to inscribe tiny channels onto their photonic chip. The team said these channels combine the incoming light from the different sources, “enabling the separate telescopes to work together as a single telescope.”
After fabrication, the team installed its light-guiding photonic chip on CHARIOT, an instrument specifically designed to test new photonic technologies. Next, the team tested the chip during the 2024 and 2025 observation campaigns. According to their statement, the photonic chip at the heart of CHARIOT “successfully combined light from telescopes at the CHARA Array and recorded signals from a range of stars, demonstrating the precision required for advanced astronomical research.”
During the campaigns, the team’s chip showed greater sensitivity than its predecessor. This included detecting light from stars fainter than those previously detected.
Dr. Aline Dinkelaker, lead author of the study from the Leibniz Institute for Astrophysics Potsdam, said these first successful observations demonstrate that photonic technologies like the custom-made chip “can deliver the performance needed for frontline astronomical research.”
“Demonstrating this technology under real observing conditions is an important step forward,” Dr. Dinkelaker added.
Observing Distant Planets in “Greater Detail”
When discussing the benefits of their approach, the team noted that one of CHARIOT’s biggest advantages is the system’s flexibility. For example, when new photonic chips are designed, the team can remove the old ones and replace them “within hours.”
The team said the successful test run also shows that a technology “small enough to fit into the palm of a hand” can perform astronomy tasks that are traditionally executed by much larger, more complicated pieces of equipment. Dr. Benoît echoed the sentiment, noting that their approach allows astronomers to “integrate complex optical functions into a remarkably small and stable glass chip.”
“Combined with the flexibility of CHARIOT, this gives us a powerful platform for rapidly testing and validating increasingly advanced photonic technologies as we develop them,” Benoît added.
Although there is still only one CHARIOT, the team suggested the approach could shape future astronomical observatories, resulting in smaller, less costly, more efficient, and more powerful observation tools. Dinkelaker said the successful tests could evolve enough to help astronomers and cosmologists tackle some of the field’s most ambitious goals, including the ‘direct’ detection and characterization of distant planets.
“As the technology develops, it could help astronomers study planetary systems around other stars in greater detail and support some of the most ambitious goals in modern astronomy,” Dinkelaker said.
The study appears in Monthly Notices of the Royal Astronomical Society (MNRAS).
Christopher Plain has spent the last six years as Associate News Editor and Head Science Reporter at The Debrief. Follow and connect with him on X, learn about his novels at plainfiction.com, or email him at christopher@thedebrief.org.