A transportable spectrometer for in situ and local measurements of iodine monoxide at mixing ratios in the 10-14 range

• Published in: Applied Physics Letters
• Main Authors: Méjean, Guillaume, Grilli, Roberto, Abd Alrahman, Chadi, Ventrillard, Irène, Kassi, Samir, Romanini, Daniele
• Other Authors: LIPhy-LAME, Université Joseph Fourier - Grenoble 1 (UJF)-Laboratoire Interdisciplinaire de Physique Saint Martin d’Hères (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), LAsers, Molécules et Environnement (LAME-LIPhy), Laboratoire Interdisciplinaire de Physique Saint Martin d’Hères (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: chemical variables measurement; gas sensors; infrared spectra; measurement by laser beam; shot noise; ultraviolet spectra; ultraviolet spectrometers; Sensors; remote sensing; Lasers; Metrological applications; optical frequency synthesizers for precision spectroscopy; Chemical analysis and related physical methods of analysis; [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]; North West Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-00996499; https://doi.org/10.1063/1.4726190

International audience We present a robust, compact, and transportable instrument that measures the iodine monoxide atmospheric radical at extremely low concentration, down to 40 ppqv (parts per quadrillion by volume, 1:1015). As nitrogen dioxide is strongly absorbed in the same spectral region it could be simultaneously measured down to 4 pptv (parts per trillion by volume, 1:1012). Relying on ''mode locked cavity-enhanced absorption spectroscopy,'' the instrument makes use of a free-running commercial femtosecond Titane Saphir laser. We demonstrate that this multiplex detection scheme provides shot noise limited spectra for acquisition times as long as 5 min. Moreover, this instrument is very versatile as it can be potentially tuned from the infrared to the ultraviolet (1080-340 nm) to reach various molecular absorptions. It has been recently deployed at the Station Biologique de Roscoff on the North West Atlantic coast of France.