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 perfor m spectrally resolved measurements of H2O transitions near 1.4 mu m. L ine-shape analyses of the recorded absorption spectra yielded the temp erature-dependent self-, N-2-, and CO2-broadened half-widths. Room-tem perature (296 K) half-widths for eight rovibrational transitions in th e v(1) + v(3) and 2v(1) vibrational bands were determined from measure ments recorded in a variable pathlength (0.4-10 m) multi-pass cell. Th e temperature dependence of the half-widths for four of the transition s were determined from measurements conducted in a heated static cell over a temperature range of 400-1000 K. The room-temperature half-widt hs and temperature exponents were determined to an average accuracy of +8%/ - 6% and +/- 9%, respectively, and are in good agreement with th eoretical calculations and published half-widths for transitions with the same rotational quantum numbers. (C) 1997 Elsevier Science Ltd.