title: Simultaneous measurement of NO and NO(2) by dual-wavelength quantum cascade laser spectroscopy.
abstract: The concept of a multi-wavelength quantum cascade laser emitting at two or more spectrally well-separated wavelengths is highly appealing for applied spectroscopy, as it allows detecting several species with compact and cost-efficient optical setups. Here we present a practical realization of such a dual-wavelength setup, which is based on a room-temperature quantum cascade laser emitting single-mode at 1600 cm-1and 1900 cm-1and is thus well-suited for simultaneous NO and NO2detection. Operated in a time-division multiplexed mode, our spectrometer reaches detection limits of 0.5 and 1.5 ppb for NO2and NO, respectively. The performance of the system is validated against the well-established chemiluminescence detection while measuring the NOx emissions on an automotive test-bench, as well as upon monitoring the pollution at a suburban site.
authors.forename: Jana
authors.initials: J
authors.lastname: Jágerská
authors.forename: Pierre
authors.initials: P
authors.lastname: Jouy
authors.forename: Béla
authors.initials: B
authors.lastname: Tuzson
authors.forename: Herbert
authors.initials: H
authors.lastname: Looser
authors.forename: Markus
authors.initials: M
authors.lastname: Mangold
authors.forename: Patrik
authors.initials: P
authors.lastname: Soltic
authors.forename: Andreas
authors.initials: A
authors.lastname: Hugi
authors.forename: Rolf
authors.initials: R
authors.lastname: Brönnimann
authors.forename: Jérôme
authors.initials: J
authors.lastname: Faist
authors.forename: Lukas
authors.initials: L
authors.lastname: Emmenegger