JQI's two-laser chip frequency comb matched the stability and noise of full benchtop optical frequency combs in a Nature paper published in 2026, while the team reports stabilizing more than 10 times the number of microcombs in the past year than across all preceding years combined.

Joint Quantum Institute research scientist Grégory Moille and JQI fellow Kartik Srinivasan led the work, which builds on nearly two decades of single-laser microresonator combs. The design adds a second laser and a synchronization technique that locks every comb tooth into alignment — what the group calls SParCS, or self-aligned parametrically-driven cavity soliton.

The collaboration with University of Auckland researcher Miro Erkintalo began after Moille and Srinivasan read a 2023 paper by Erkintalo's team predicting parametrically driven cavity solitons. The two groups reported producing PDCS in 2024. The Nature paper now extends those physics results into a measurement-grade device.

Why two lasers instead of one?

Single-laser combs spread teeth symmetrically around a central frequency, with the outermost teeth losing power and sharpness. SParCS uses two lasers at octave-spaced frequencies as bookends. The comb teeth form between them, concentrating power where measurement applications need it most.

The octave span matters practically. The standard technique for finding the comb's zero-frequency offset — the method that earned its creators the 2005 Nobel Prize in physics — requires teeth separated by a factor of two in frequency. SParCS lets researchers pick laser frequencies that guarantee the critical edge teeth are usable without amplification hardware.

Even with two pump lasers, the overall setup shrinks because competing approaches still need a second laser plus amplifiers to boost weak edge teeth.

How well did the chip perform?

Moille ran three head-to-head tests against a standard tabletop comb:

• Linking microwaves to optical light, with potential uses in lidar and other distance-measuring systems.
• Tying optical light from an AFRL-supplied stable atomic clock reference to a microwave signal, then measuring the original light's frequency to within about 100,000 oscillations per second of the value the atoms should produce.
• Pairing a UCSB-supplied low-noise laser with the comb to produce ultrapure microwave frequencies for radar and related uses.

All three measurements used the same SParCS device, with only the partner laser swapped. Previous on-chip demonstrations required a tailored microcomb for each application.

What does this change for deployable systems?

Portable atomic clocks remain the headline target. They could map underground mineral deposits and back up navigation when GPS signals are unavailable. Moille, also a NIST associate, framed atomic timekeeping as the most demanding near-term test of the technology.

"With this new approach, we finally see a viable path for their use in deployable atomic timekeeping, which is one of their most demanding and important applications," Moille said.

Srinivasan, who is also a NIST fellow, put numbers on the lab's shift: "Our lab, as of 18 months ago, was 90% dedicated to the typical approach of pumping in the center and then extending out to the edges. We've now switched all these experiments to focus on the new SParCS approach. Within the last year, we've been able to stabilize more than 10 times the number of microcombs than we had across all the preceding years combined, and that's why we feel so strongly that this approach has a lot of potential going forward."

The SParCS design also forgives fabrication variation. The team performed measurements on devices with several different layouts, all of which produced usable results with simple adjustments — a property the researchers cite as relevant to volume manufacturing of photonic chips.

What's next?

The group is pushing toward larger frequency ranges and exploring whether a single laser could feed both ends of the comb. The combs are now in use as tools across other JQI experiments, replacing a setup Srinivasan said required "a team of several people working for weeks or months" to produce practical results for a single application. With SParCS, "you actually have only one operator at a time doing each application," Moille said.

The published paper — "Self-aligned optical microcomb emerging between octave-separated lasers" by Grégory Moille et al, Nature (2026), DOI 10.1038/s41586-026-11086-2 — is the clearest signal yet that chip-scale frequency combs have moved from physics demonstrations toward deployable metrology hardware.