title: Temperature-dependent, nitrogen-perturbed line shape measurements in the ν1 + ν3 band of acetylene using a diode laser referenced to a frequency comb.
abstract: The P(11) line of the ν1 + ν3 combination band of C2H2 was studied using an extended cavity diode laser locked to a frequency comb. Line shapes were measured for acetylene and nitrogen gas mixtures at a series of temperatures between 125 and 296 K and total pressures up to 1 atm. The data were fit to two speed-dependent line shape models and the results were compared. Line shape parameters were determined by simultaneously fitting data for all temperatures and pressures in a single multispectrum analysis. Earlier pure acetylene measurements [Cich et al. Appl. Phys. B 2012, 109, 373-38] were incorporated to account for self-perturbation. The resulting parameters reproduce the observed line shapes for the acetylene-nitrogen system over the range of temperatures and pressures studied with average root-mean-square observed-calculated errors of individual line measurement fits of approximately 0.01% of maximum transmission, close to the experimental signal-to-noise ratios. Errors in the pressure measurements constitute the major systematic errors in these measurements, and a statistical method is developed to quantify their effects on the line shape parameters for the present system.
authors.affiliation: Department of Chemistry, Stony Brook University , Stony Brook, New York 11794, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cich
authors.forename: Damien
authors.initials: D
authors.lastname: Forthomme
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McRaven
authors.forename: Gary V
authors.initials: GV
authors.lastname: Lopez
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Hall
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Sears
authors.forename: Arlan W
authors.initials: AW
authors.lastname: Mantz