DIODE-LASER ABSORPTION-MEASUREMENTS OF CH3CL AND CH4 NEAR 1.65 MU-M

Two distributed-feedback (InGaAsP) diode lasers were used to record hi gh-resolution absorption spectra of the parallel and the perpendicular components of the 2 nu(4) band of methyl chloride (CH3Cl) and the 2 n u(3) band of methane (CH4) near 1.65 mu m. The room-temperature absorp tion measurements, which were conducted in a multipass cell with a var iable path length (878-1020 cm), were used to determine the mole fract ions of the constituent gases and thus demonstrate species-specific, n onintrusive concentration measurements of species with overlapping spe ctra. (C) 1997 Optical Society of America.