Ra. Cheville et D. Grischkowsky, Far-infrared foreign and self-broadened rotational linewidths of high-temperature water vapor, J OPT SOC B, 16(2), 1999, pp. 317-322
We report what is believed to be the first measurement of rotational line b
roadening of high-temperature water vapor for transition frequencies that r
ange from 1.0 to 2.5 THz (33 to 83 cm(-1)). Water-vapor rotational transiti
ons were measured in a near-stoichiometric propane-air flame at 1490 K with
THz time-domain spectroscopy. Linewidths were measured for 29 pure rotatio
nal transitions in both ground vibrational and nu(2) = 1 vibrational levels
with lower state energies ranging from 80 to 2390 cm(-1). Measured widths
show a dependence on rotational state energy that roughly follows a thermal
distribution with variation between various J, K-a, K-c rotational quantum
numbers. (C) 1999 Optical Society of America [S0740-3224(99)01002-4].