title: Sensitive wavelength-modulated photoacoustic spectroscopy with a pulsed optical parametric oscillator.
abstract: With a laser-excited acoustic wave as the carrier wave and by modulation of the light wavelength of a multikilohertz-repetition-rate optical parametric oscillator at a lower frequency than the acoustic frequency, we demonstrate a wavelength-amplitude double-modulation technique and achieve an enhancement factor of 35 in sensitivity in photoacoustic trace gas detection with the technique.
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Ng
authors.forename: A H
authors.initials: AH
authors.lastname: Kung
authors.forename: András
authors.initials: A
authors.lastname: Miklós
authors.forename: Peter
authors.initials: P
authors.lastname: Hess