Diode laser spectroscopy of H216O spectra broadened by N2 and He in 1.39 µm region

- Measurements of water vapor spectra at 1.39 μm region in mixtures with N2 and Ne.
- Line parameters of 6 spectral lines were retrieved using the multispectrum fitting procedure.
- Voigt, Galatry, and Speed-dependent Voigt profiles were used for fitting.

Experimental spectra of pure water vapor and its mixtures with N2 and He were measured in a pressure range (4-19 for pure H2O and 70-630 mBar for H2O diluted in N2 and Ne) by the diode laser spectrometer between 7184 and 7186 cm−1. The noise equivalent absorption cross-section of the all observed spectra varied from 1.2 to 4.3×10-24 cm2/molec allowing signal to noise ratio from 10 for weak (intensity on the order of 5×10-25 cm/molec at 296 K) to 15,000 for strong (intensity on the order of 6×10-22 cm/molec) spectral lines respectively. The Voigt, Galatry, and Speed-dependent Voigt (SDV) profiles were used to fit the experimental spectra. This region includes 7 absorption lines of H2O and one HDO line according to the new line lists of H2O. Line positions, intensities, line shift, collisional broadening and narrowing coefficients for 6 spectral lines were retrieved by multispectrum fitting procedure assuming the linear pressure dependence. The spectral parameters of the doublet (ν1+ν3; 660←661; 661←660) at 7185.596 cm−1 were determined for the first time.