Diode-laser measurements of temperature-dependent half-widths of H2O transitions in the 1.4 mu m region

Two distributed-feedback InGaAsP diode lasers have been used to perform spectrally resolved measurements of H2O transitions near 1.4 mu m. Line-shape analyses of the recorded absorption spectra yielded the temperature-dependent self-, N-2-, and CO2-broadened half-widths. Room-temperature (296 K) half-widths for eight rovibrational transitions in the v(1) + v(3) and 2v(1) vibrational bands were determined from measurements recorded in a variable pathlength (0.4-10 m) multi-pass cell. The temperature dependence of the half-widths for four of the transitions were determined from measurements conducted in a heated static cell over a temperature range of 400-1000 K. The room-temperature half-widths and temperature exponents were determined to an average accuracy of +8%/ - 6% and +/- 9%, respectively, and are in good agreement with theoretical calculations and published half-widths for transitions with the same rotational quantum numbers. (C) 1997 Elsevier Science Ltd.