5 Key Takeaways

• 1

  Dual-comb spectroscopy uses two optical frequency combs with slightly different pulse rates to convert optical spectra into electronically measurable radio frequencies.

• 2

  The technique can acquire detailed spectra rapidly, with high spectral resolution and precise frequency measurements, without moving components used in some conventional instruments.

• 3

  Mid-infrared spectra capture strong molecular vibrations, while terahertz spectra reveal molecular rotations, weak intermolecular interactions, and collective motions in solids.

• 4

  The review compared comb-generation technologies and described applications in gas analysis, environmental monitoring, combustion studies, and research on biological materials.

• 5

  Biomedical applications remain at the research stage, and technical barriers include limited spectral coverage, detector noise, cooling, alignment, complexity, and coherence maintenance.