WATER-VAPOR ABSORPTION-LINE MEASUREMENTS IN THE 940-NM BAND BY USING A RAMAN-SHIFTED DYE-LASER

We report water-vapor absorption line measurements that are made by using the first Stokes radiation (930-982 nm) with HWHM 0.015 cm-1 generated by a narrow-linewidth, tunable dye laser. Forty-five absorption line strengths are measured with an uncertainty of 6% and among them are fourteen strong lines that are compared with previous measurements for the assessment of spectral purity of the light source. Thirty air-broadened linewidths are measured with 8% uncertainty at ambient atmospheric pressure with an average of 0.101 cm-1. The lines are selected for the purpose of temperature-sensitive or temperature-insensitive lidar measurements. Results for these line strengths and linewidths are corrected for broadband radiation and finite laser linewidth (0.015 cm-1 HWHM) broadening effects and compared with the high-resolution transmission molecular absorption.