Two distributed-feedback (InGaAsP) diode lasers were used to record high-resolution absorption spectra of the parallel and the perpendicular components of the 2ν4 band of methyl chloride (CH3Cl) and the 2ν3 band of methane (CH4) near 1.65 µm. The room-temperature absorption measurements, which were conducted in a multipass cell with a variable path length (878–1020 cm), were used to determine the mole fractions of the constituent gases and thus demonstrate species-specific, nonintrusive concentration measurements of species with overlapping spectra.
© 1997 Optical Society of America
Original Manuscript: August 26, 1996
Revised Manuscript: January 7, 1997
Published: May 20, 1997
Shang-I Chou, Douglas S. Baer, and Ronald K. Hanson, "Diode laser absorption measurements of CH3Cl and CH4 near 1.65 µm," Appl. Opt. 36, 3288-3293 (1997)