title: Part-per-trillion level SF6 detection using a quartz enhanced photoacoustic spectroscopy-based sensor with single-mode fiber-coupled quantum cascade laser excitation.
abstract: A sensitive spectroscopic sensor based on a hollow-core fiber-coupled quantum cascade laser (QCL) emitting at 10.54 μm and quartz enhanced photoacoustic spectroscopy (QEPAS) technique is reported. The design and realization of mid-IR fiber and coupler optics has ensured single-mode QCL beam delivery to the QEPAS sensor. The collimation optics was designed to produce a laser beam of significantly reduced beam size and waist so as to prevent illumination of the quartz tuning fork and microresonator tubes. SF(6) was selected as the target gas. A minimum detection sensitivity of 50 parts per trillion in 1 s was achieved with a QCL power of 18 mW, corresponding to a normalized noise-equivalent absorption of 2.7×10(-10) W·cm(-1)/Hz(1/2).
authors.affiliation: Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN UOS BARI, Bari, Italy. spagnolo@fisica.uniba.it
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Spagnolo
authors.forename: Pietro
authors.initials: P
authors.lastname: Patimisco
authors.forename: Simone
authors.initials: S
authors.lastname: Borri
authors.forename: Gaetano
authors.initials: G
authors.lastname: Scamarcio
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Bernacki
authors.forename: Jason
authors.initials: J
authors.lastname: Kriesel