PRESSURE BROADENING AND SHIFT OF SOME H2O LINES IN THE NU(2) BAND - REVISITED

Pressure-induced line broadening and line shift of three rovibrational transitions in the v(2) band and three in the 2v(2) - v(2) hot band o f H2O at 7 mu m were remeasured, using the wavelength-stabilized Colog ne diode laser spectrometer with an upgraded recording system: the det ermination of the absolute line positions was better than 1 MHz, where as the sensitivity and the long-term stability were improved by at lea st a factor of 10. The shift coefficient was found to be linearly depe ndent on the mixing ratio of the foreign gases oxygen and nitrogen for all transitions investigated, including the 13(2,12) <-- 14(1,13) tra nsition for which we previously reported a nonlinear behavior. This gr eatly improved consistency of the experimental data sets allows a chec k on the applicability of various profile functions: a comparison betw een the Galatry and a Voigt profile function with floating Doppler wid th indicates that both reproduce the experimental values very well. Pu rely the ease of use gives the edge to the Voigt profile with floating Doppler width. (C) 1997 Academic Press.