title: Precision measurements of NH(3) spectral lines near 11 microm using the infrared heterodyne technique.
abstract: Absolute line-center frequencies for eleven lines of ammonia in near coincidence with CO(2)-laser transitions have been determined to accuracies of +/-3 MHz by infrared heterodyne detection. These results were obtained by heterodyning a blackbody with a stable, grating-tuned CO(2) gas laser. A discussion of the apparatus and method of calculation, including error analysis, is presented. With these accurately determined line-center positions, the ammonia molecule will be a useful secondary-frequency standard for diode-laser spectroscopy in the 11-microm wavelength region.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hillman
authors.forename: T
authors.initials: T
authors.lastname: Kostiuk
authors.forename: D
authors.initials: D
authors.lastname: Buhl
authors.forename: J L
authors.initials: JL
authors.lastname: Faris
authors.forename: J C
authors.initials: JC
authors.lastname: Novaco
authors.forename: M J
authors.initials: MJ
authors.lastname: Mumma