ICLAS-VeCSEL and FTS spectroscopies of C2H2 between 9000 and 9500 cm−1

The acetylene absorption spectrum has been recorded between 1.10 and 1.05 μm by Fourier Transform Spectroscopy (FTS) and Intracavity Laser Absorption Spectroscopy (ICLAS) based on a Vertical external Cavity Surface Emitting Laser (VeCSEL). Eleven bands of 12C2H2 were detected, six of them being newly reported. The spectroscopic parameters retrieved from the rovibrational analyses improve significantly the accuracy of parameter values available in the literature. One additional band is assigned to the 13C12CH2 isotopologue, present in natural abundance in the sample. Finally, three bands newly detected near 12 300 cm−1 by ICLAS based on a Ti:Sapphire are also reported. The vibrational upper states are unambiguously assigned on the basis of the effective Hamiltonian model and the observed and predicted vibrational term values are found in good agreement.