Mid-infrared intracavity quartz-enhanced photoacoustic spectroscopy with pptv - Level sensitivity using a T-shaped custom tuning fork

Jakob Hayden; Marilena Giglio; Angelo Sampaolo; Vincenzo Spagnolo; Bernhard Lendl

doi:10.1016/j.pacs.2022.100330

Mid-infrared intracavity quartz-enhanced photoacoustic spectroscopy with pptv - Level sensitivity using a T-shaped custom tuning fork

Photoacoustics. 2022 Jan 11:25:100330. doi: 10.1016/j.pacs.2022.100330. eCollection 2022 Mar.

Authors

Jakob Hayden¹, Marilena Giglio², Angelo Sampaolo², Vincenzo Spagnolo², Bernhard Lendl¹

Affiliations

¹ Institute of Chemical Technologies and Analytics, Technische Universität Wien, Getreidemarkt 9, 1060 Vienna, Austria.
² PolySense Lab - Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, Bari, Italy.

Abstract

Resonant optical power buildup inside a high finesse cavity is exploited to boost the sensitivity in quartz-enhanced photoacoustic spectroscopy (QEPAS) for CO, N₂O and H₂O detection, operating at a wavelength of 4.59 µm. A quartz tuning fork with T-shaped prongs optimized for QEPAS has been employed. Exploiting the high signal-to-noise ratio attainable with this tuning fork together with an optical power amplification of ~100 enabled by efficient optical feedback locking, limits of detection (3σ, 10 s integration) of 260 ppt and 750 ppt for CO and N₂O have been reached.

Keywords: Cavity enhanced spectroscopy; Costum quartz tuning fork; QEPAS; Quantum cascade laser; Trace gas sensing.