Physicists at Loughborough University, working with an international team, have shown that a microchip no bigger than a grain of rice can generate a stable “microcomb” of light frequencies and convert them into multiple, precisely spaced millimeter-wave signals at once. The breakthrough, reported in Nature Communications, tackles a key bottleneck for future high-capacity communications and other technologies that rely on ultra-stable, high-frequency signals.
Why millimeter waves matter
Millimeter waves sit at the high-frequency end of the radio spectrum and offer far more bandwidth than today’s wireless bands, meaning more data can be sent faster and in higher resolution.
That makes them attractive for next-generation 6G networks, as well as advanced radar, spectroscopy and astronomical instruments that demand extreme measurement precision.
“The world is becoming increasingly data hungry,” said Dr Luke Peters of Loughborough’s Emergent Photonics Research Centre. “We want to send and receive more information, faster and in higher resolution, and millimeter waves could help provide the capacity to do that.”
The microcomb breakthrough
One promising route to millimeter waves is via a microcomb, a tightly spaced spectrum of optical frequencies, like an invisible rainbow, that can be converted into radio signals using a specialized antenna.
Earlier work typically produced a single, precise millimeter-wave frequency from a microcomb; generating many at once would open multiple data channels but requires exceptional clarity and stability.
In the new study, the Loughborough-led team created exactly that, a stable, high-quality microcomb that yields multiple precisely spaced millimeter-wave frequencies simultaneously.
The trick lies in how the microcomb is generated. Instead of relying only on a tiny on-chip microresonator, the team couples it to a larger loop of optical fiber so laser light continuously circulates through both.
“We’ve essentially created an incredibly precise and stable ‘rainbow on a chip,’ where the loop keeps feeding the light back through the chip, allowing these states to build up efficiently, start on their own and remain stable even when the system is disturbed,” Peters said. The setup is remarkably robust—researchers observed the microcomb holding steady even with people jumping nearby.
Tunable, stable signals for real applications
The team also demonstrated control over the microcomb’s “rainbow,” boosting or suppressing individual frequencies as needed. Crucially, that precision and stability carried through to the millimeter-wave signals, producing a set of highly controlled, accurately spaced radio frequencies.
“Being able to make individual frequencies stronger or weaker gives us much more control over the signals we produce, because different applications will need different combinations of frequencies,” Peters said. That level of control is valuable not only for communications but also for timing-sensitive systems underpinning emerging quantum technologies.
From lab bench to shoebox and maybe satellites
While the core microchip is tiny, the current demonstration is still a tabletop laboratory system.
The researchers envision future versions that are more compact and energy-efficient, potentially small enough to fit inside a shoebox.
One target application is space, the team is particularly interested in whether the technology could eventually be used on satellites, where size, weight and power are at a premium.
Precision timing and quantum-enabled navigation
Beyond communications, the group is probing just how accurate the microcomb can be by testing it against precision clocks. Through collaborations with the UK’s National Physical Laboratory and the National Quantum Computing Centre – linked Hub for Quantum Enabled Position, Navigation and Timing (QEPNT), they’re exploring uses in timing, navigation and positioning.
“We’re really excited to see how far we can take the precision and stability of these microcombs, particularly for technologies that rely on extremely accurate timing,” said Dr Antonio Cutrona, who led the microcomb stability measurements. The hope is to bring atomic-clock-level precision into more compact devices for timing, navigation and position—potentially reshaping how future systems keep time and know where they are.
Source: L. Peters et al., “Millimetre-wave comb generated by an optical microcomb,” Nature Communications (2026). DOI: 10.1038/s41467-026-76747-2.
Related coverage: ‘Rainbow-on-a-chip’ could help unlock 6G networks and precision timing for quantum technologies
Publication details
- Peters et al, Millimetre-wave comb generated by an optical microcomb, Nature Communications(2026). DOI: 10.1038/s41467-026-76747-2
Journal information: Nature Communications
