title: Stark-effect-modulated phase-fluctuation optical heterodyne interferometer for trace-gas analysis.
abstract: A narrow-bandwidth (cw) phase-fluctuation laser-heterodyne interferometer for trace-gas detection is described. Performance was evaluated using both Stark-effect modulation and conventional beam chopping. Sensitivities of 10(-8) cm(-1) were obtained in both cases. However, when Stark-effect modulation was employed, the usual background signal caused by interfering absorbing species and windows could be subtracted from the overall signal. In this mode, a detection limit of 5 parts in 10(9) (ppb) NH(3) in air was obtained.
authors.forename: A J
authors.initials: AJ
authors.lastname: Campillo
authors.forename: H B
authors.initials: HB
authors.lastname: Lin
authors.forename: C J
authors.initials: CJ
authors.lastname: Dodge
authors.forename: C C
authors.initials: CC
authors.lastname: Davis