05 Jun Dual-comb technique advances spectroscopy
In metrology, a laser frequency comb serves as a precise optical ruler in the frequency domain. It consists of a spectrum of sharp laser lines arranged at perfectly regular intervals. Such frequency combs, based on mode-locked femtosecond lasers, were developed in the 1990s at the Max Planck Institute of Quantum Optics.
Over the past two decades, frequency combs have found a range of new applications. One of the most important is dual-comb spectroscopy. This technique combines broad spectral coverage with high resolution and accuracy by using two optical frequency combs with slightly different repetition rates. Dual-comb spectroscopy relies on time-domain interferometry and eliminates the need for mechanical scanning, enabling precise, rapid and broadband measurements.
Professor Nathalie Picqué of the Max Born Institute and Humboldt University of Berlin, together with Nobel Laureate Professor Theodor W. Hänsch of the Max Planck Institute of Quantum Optics and Ludwig Maximilian University of Munich, have now published a review article outlining the principles, recent advances and future prospects of the rapidly evolving field of broadband atomic and molecular science based on dual-comb spectroscopy.
The authors highlight that the dual-comb interferometer, free from geometric constraints, provides a conceptual pathway toward broadband spectroscopy in which resolution is determined solely by temporal coherence. The approach also opens the door to highly miniaturized spectrometers.
Dual-comb spectroscopy has now been implemented across nearly the entire electromagnetic spectrum, from the terahertz region to the visible range, with current efforts extending into the ultraviolet. Applications range from fundamental studies in quantum electrodynamics and investigations of molecular structures to environmental sensing, biomedical diagnostics and industrial monitoring.
Original Publication
[Picqué, N., Hänsch, T.W.: Dual-comb spectroscopy; Nature Reviews Methods Primers 6, 36 (2026), https://doi.org/10.1038/s43586-026-00481-8]
Direct weblink to the article via Nature SharedIt
Source: mbi-berlin.de
Image: Nathalie Picqué / MBI