Mid-infrared high-resolution dual-comb spectroscopy: Intensity, broadening, and beyond-Voigt parameters of 12C2H2 and 13C12CH2 lines

Using a high-resolution mid-infrared dual-comb spectrometer operating in the 1300 cm(-1) spectral region, spectra of acetylene were recorded at room temperature. Spectroscopic parameters were measured in 3 vibrational bands of both (C2H2)-C-12 and (C12CH2)-C-13. Absolute line intensities (S-0) and self-broadening coefficients (gamma(self)(0)) were determined in the nu(4) + nu(5), 2 nu(2)(4) + nu(-1)(5) <- nu(1)(4) and nu(1)(4) + 2 nu(0)(5) <- nu(1)(5) bands. For the main isotopologue, the collisional narrowing coefficients nu(VC)(0)) as well as the speed-dependence of the broadening (gamma(2)) and shifting (delta(2)) coefficients were measured in the nu(4) + nu(5) band of the main isotopologue of acetylene. Theoretical line-shape models were fitted on experimental profiles using a homemade multi-spectrum fitting procedure to determine spectroscopic parameters. Excellent agreement with the literature was found for self-broadening coefficients and absolute line intensities in the nu(4) + nu(5) band of (C2H2)-C-12. For the hot bands, good agreement with the literature is found within experimental uncertainties, while gamma(self)(0) of those hot bands are also reported for the first time. Similarly, the rotational dependence of nu(VC)(0) is found to be close to previous works. gamma(2) and delta(2) of (C2H2)-C-12, as well as S-0 and gamma(self)(0) of (C12CH2)-C-13 are also reported for the first time in this band.