title: Optical parametric oscillator based off-axis integrated cavity output spectroscopy for rapid chemical sensing.
abstract: An optical parametric oscillator (OPO), pumped by a fiber-amplified diode laser, is combined with off-axis integrated cavity output spectroscopy (OA-ICOS). The cw OPO (power 1.2 W, tunability 3-4 μm, 5 cm(-1) mode-hop-free tuning) has a tuning speed of 100 THz/s, which is ideal for rapid and sensitive trace gas detection. Combined with OA-ICOS, a detection limit of 50 parts per trillion by volume (1×10(12)) of ethane (C(2)H(6)) in nitrogen was obtained in 0.25s at 2997 cm(-1), corresponding to a noise equivalent absorption sensitivity of 4.8×10(-11) cm(-1) Hz(-1/2). The system demonstrates real-time measurements of methane and water in exhaled human breath.
authors.affiliation: Life Science Trace Gas Facility, Molecular and Laser Physics, Radboud University, Heyendaalseweg 135, Nijmegen 6525AJ, The Netherlands. d.arslanov@science.ru.nl
authors.forename: Denis D
authors.initials: DD
authors.lastname: Arslanov
authors.forename: Simona M
authors.initials: SM
authors.lastname: Cristescu
authors.forename: Frans J M
authors.initials: FJ
authors.lastname: Harren
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D045853:Exhalation; D006801:Humans; D007834:Lasers; D008697:Methane / Q000032:analysis; D055620:Optical Phenomena; D013057:Spectrum Analysis; D014867:Water / Q000032:analysis
chemical_list: D014867:Water; D008697:Methane