New Chip-Based Technology Could Revolutionize Atomic Clocks and Precision Measurement
Researchers from the University of Auckland and collaborators in the U.S. have developed a chip-based optical frequency comb that shows potential for creating smaller, more portable precision measurement devices, including atomic clocks. This innovation could significantly broaden the applications of this technology in fields such as navigation, telecommunications, and sensing.
The team’s advancements, featuring a novel design using two lasers with frequencies an octave apart, effectively address issues of control and stabilization that have historically limited the use of optical frequency combs outside laboratory settings. These combs produce evenly spaced light frequencies, often referred to as “light rulers” or “rainbow rulers,” essential for measuring optical frequencies.
Professor Miro Erkintalo, head of the Department of Physics at the University of Auckland and a researcher with the Dodd-Walls Centre for Photonic and Quantum Technologies, initiated this research in 2021. He predicted that two laser beams could be manipulated within a chip-scale ring to generate a frequency comb, a concept demonstrated in 2024 in collaboration with researchers from the University of Maryland and the U.S. National Institute of Standards and Technology.
Following this proof-of-concept demonstration, the research team has now successfully implemented the new comb technology. Their recent work showcases the system’s ability to generate precise optical frequencies, produce low-noise millimetre-wave signals, and perform integrated optical clock readouts.
“This work is the culmination of several years of effort,” Erkintalo stated. “It demonstrates how innovative technological applications can emerge from research driven by curiosity.” The original optical frequency comb concept was developed in the late 1990s, earning John Hall and Theodor Hänsch a Nobel Prize in Physics in 2005.
By miniaturizing optical frequency combs, researchers aim to expand the technology beyond the lab. Potential uses for portable optical atomic clocks include mapping underground mineral deposits and providing navigation solutions that do not rely on GPS satellite signals. Grégory Moille from the University of Maryland pointed out that traditional systems often struggle with control and stabilization, but this new approach offers a promising pathway for practical applications in atomic timekeeping.
The redesign flips the conventional frequency comb architecture by utilizing two distant lasers to automatically fill in the spectrum, rather than relying on a single laser’s cascading light. This advancement paves the way for opportunities in telecommunications synchronization and highly sensitive environmental sensing.
The research, published in the journal Nature, suggests that reducing the size, weight, power consumption, and cost of optical frequency combs could lead to their mass production and transition from laboratory use to consumer applications. Erkintalo, Moille, and Srinivasan have already submitted a provisional patent application based on their findings.
