title: External cavity diode laser-based detection of trace gases with NICE-OHMS using current modulation.
abstract: We combine an external cavity diode laser with noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) using current modulation. With a finesse of 1600, we demonstrate noise equivalent absorption sensitivities of 4.1 x 10(-10) cm(-1) Hz(-1/2), resulting in sub-ppbv detection limits for Doppler-broadened transitions of CH(4) at 6132.3 cm(-1), C(2)H(2) at 6578.5 cm(-1) and HCN at 6541.7 cm(-1). The system is used for hydrogen cyanide detection from sweet almonds.
authors.forename: R
authors.initials: R
authors.lastname: Centeno
authors.forename: J
authors.initials: J
authors.lastname: Mandon
authors.forename: S M
authors.initials: SM
authors.lastname: Cristescu
authors.forename: O
authors.initials: O
authors.lastname: Axner
authors.forename: F J M
authors.initials: FJ
authors.lastname: Harren