2024

Reference-free dual-comb spectroscopy with inbuilt coherence

PriSpecTemp's project partner, the University of Helsinki, published an article titled "Reference-free dual-comb spectroscopy with inbuilt coherence," in the prestigious journal Optics Letters [1]. Dual-comb Fourier-transform spectroscopy (FTS) combines the advantages of laser spectroscopy and classic FTS, offering high precision, speed, and broadband coverage.

The first successful demonstration of dual-comb spectroscopy in gas thermometry was reported in 2018 by Shimizu et al. at the National Metrology Institute of Japan [2]. However, improving the signal-to-noise ratio of the measurements is critical in order to enhance the accuracy of derived gas temperatures. Another important area for further development is to simplify the experimental implementation and ensure its robustness for practical applications.

Prof. Markku Vainio, the last author of the Optics Letters article, explains the key enabler for this scientific advance: "Dual-comb spectroscopy has proven a powerful technology for high-precision gas spectroscopy, but its implementation is often technically involved, requiring optical phase locking and fast control electronics. In our work, we have shown that the experimental implementation can be significantly simplified without sacrificing the measurement precision. This is a step towards practical and accurate gas thermometry using dual-comb spectrometers."
 

[1] M. Roiz, S. Larnimaa, T. Uotila, M. Närhi, and M. Vainio, "Reference-free dual-comb spectroscopy with inbuilt coherence," Opt. Lett. 49, 2473-2476 (2024). https://doi.org/10.1364/OL.521866

[2] Y. Shimizu et al., “Molecular gas thermometry on acetylene using dual-comb spectroscopy: analysis of rotational energy distribution,” Appl. Phys. B 124, 71 (2018). https://doi.org/10.1007/s00340-018-6933-x

This work is partly supported by the European Metrology Partnership project "22IEM03 PriSpecTemp", which received funding from EPM Programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and motivation program.