Applications of Time-Resolved Mid-Infrared Dual-Comb Spectroscopy in Chemical Physics and Atmospheric Chemistry

Mid-infrared time-resolved spectroscopy with high sensitivity and spectral resolution offers powerful opportunities to investigate transient light–matter interactions, as well as probing short-lived free radicals and unstable reaction intermediates. Dual-comb spectroscopy, as an emerging Fourier transform spectroscopic technique based on two frequency combs with slightly different repetition rates, enables rapid, broadband, and high-resolution spectral measurements. Here, a new approach to time-resolved infrared laser spectroscopy based on dual-comb interferometry will be presented. In addition to introducing the unique capabilities of time-resolved dual-comb spectrometers [1–3], applications including precision measurements of line strengths of important atmospheric radicals, as well as accurate determinations of reaction rate coefficients for key atmospheric chemical reactions, will be reported [4–7].[1] P.-L. Luo and E.-C. Horng, Commun. Chem., 3, 95 (2020). [2] P-L. Luo, Opt. Lett., 45, 6791 (2020). [3] P.-L. Luo and I-Y. Chen, Anal. Chem. 94, 5752 (2022). [4] C.-W. Chang, I-Y. Chen, C. Fittschen, and P.-L. Luo, J. Chem. Phys., 159, 184203 (2023). [5] I-Y. Chen, C.-W. Chang, C. Fittschen, and P.-L. Luo, J. Phys. Chem. Lett., 15, 3733 (2024). [6] C.-W. Chang, I-Y. Chen, and P.-L. Luo, J. Chem. Phys., 162, 034302 (2025). [7] I-Y. Chen, C.-W. Chang, Q.-R. Huang, J.-L. Kuo, and P.-L. Luo, Phys. Chem. Chem. Phys., 27, 16123 (2025).