Difference-frequency spectroscopy of water in the 600-1300 GHz region.

We present a coherent dataset of water absorption line parameters obtained by direct absorption spectroscopy with a setup based on a difference frequency terahertz (THz) spectrometer designed as described in L. Djevahirdjian et al., Nat. Commun., 2023, 14(1), 7162. This study includes a demonstration of system linearity and fringe analysis, revealing beyond-Voigt signatures in the line profiles. The results are compared with the literature values, and new line parameters are reported.