QEPAS sensor using a radial resonator

• Published in: Applied physics. B, Lasers and optics Vol. 127; no. 11
• Main Authors: Duquesnoy, M., Aoust, G., Melkonian, J.-M., Levy, R., Raybaut, M., Godard, A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2021; Springer Nature B.V; Springer Verlag
• Subjects: Acetylene; Acoustics; Applied physics; Configurations; Engineering; Engineering Sciences; Finite element method; Laser beams; Lasers; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Quartz; Resonators; Sensors; Photoacoustique; Tuning forks; Spectroscopie laser; Diapasons; Laser spectroscopy; Photoacoustics
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-021-07699-2

We report on the use of a radial acoustic resonator to increase the acoustic signal of a quartz enhanced photoacoustic spectroscopy (QEPAS) sensor. This approach is an attractive alternative to usual configurations based on microtube longitudinal resonators since it enables to substantially relax laser beam alignment and positioning and thus paves the way towards more cost-effective industrial production. This new QEPAS configuration is first investigated and designed by finite element simulation. It is then experimentally implemented and characterised by detecting acetylene around 1.5 µm. The combination of the radial acoustic resonator with a custom quartz tuning fork (QTF) leads to a QEPAS sensor with a normalised noise equivalent absorption (NNEA) of 3.9 × 10 - 9 W cm - 1 Hz - 1 / 2 which is close to the performance of state-of-the-art QEPAS sensors based on microtube resonators.