Mid-infrared Dual-comb Spectroscopy as Sensor: Fast and Precise Quantification of Multiple Gases

Dual-comb spectroscopy allows to record broadband transmission spectra fast and precisely. This bridges the gap between classical methods, where Fourier-Transform infrared spectroscopy excels in spectral bandwidth or tunable laser absorptions spectroscopy in sensitivity. Here we present a dualcomb based spectrometer for gas sensing in mid-infrared from 3 mm to 5 mm. Using the spectrometer as a sensor for a mixture of nitrous oxide (N2O) and carbon monoxide (CO) results in 48.3(2) ppm N2O and 29.10(7) ppm CO in 10 s. The limits of detection are 90 ppb N2O and 49 ppb CO in 25 s.