title: Phase-shift cavity ring-down spectroscopy using mid-IR light from a difference frequency generation PPLN waveguide.
abstract: Approximately 200 microW of mid-infrared (mid-IR) light around 3081 cm(-1), produced by difference frequency generation (DFG) in a periodically poled lithium niobate crystal waveguide, has been used for phase-shift cavity ring-down spectroscopy measurements. The overlapping (12)C(2)H(4) (R)P(0)(14) and (P)R(6)(10) and (12)CH(2) (13)CH(2) (P)Q(3)(10) rotational lines of the nu(9) fundamental ethene vibrational band at 3081.0016 cm(-1) were probed in proof-of-principle experiments, and ethene detection was demonstrated with a minimum absorption coefficient of 1.4 x 10(-7) cm(-1) (approximately 4 min acquisition time). The compact DFG system, with a >35 cm(-1) tuning range, has a considerable potential for use in trace gas detection and in molecular spectroscopy.
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
authors.forename: Roberto
authors.initials: R
authors.lastname: Grilli
authors.forename: Luca
authors.initials: L
authors.lastname: Ciaffoni
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Orr-Ewing