A cavity-enhanced MEMS-based photoacoustic sensor for ppt-level trace-gas detection
Year: 2025
Authors: Pelini J., Dello Russo S., Wang Z., Galli I., Pastor PC., Garcia IL., Canino M.C., Roncaglia A., Akikusa N., Ren W., De Natale P., de Cumis M.S., Borri S.
Autors Affiliation: Univ Federico II, Corso Umberto 140, I-80138 Naples, Italy; CNR, INO Ist Nazl Ottica, via N Carrara 1, I-50019 Sesto Fiorentino, Italy; LENS, via N Carrara 1, I-50019 Sesto Fiorentino, Italy; Ctr Geodesia Spaziale, ASI Agenzia Spaziale Italiana, I-75100 Matera, Italy; Chinese Univ Hong Kong, Dept Mech & Automat Engn, Hong Kong, Peoples R China; Consiglio Nazl Ric CNR, Ist Microelettron & Microsistemi IMM, Via P Gobetti 101, I-40129 Bologna, Italy; Hamamatsu Photon KK, Hamamatsu, Shizuoka, Japan.
Abstract: Part-per-trillion level trace-molecule detection is becoming increasingly crucial fora variety of fields in our modern society, from climate change monitoring and mitigation to health studies, from industrial processes control to safety and security. The race towards more performing sensors is witnessing a rapid evolution of photoacoustic systems, whose high degree of flexibility allows them to merge their robustness and compactness to cavity-enhanced configurations, boosting their ultimate sensitivity. This work proposes an advanced configuration of a cavity-enhanced cantilever-based photo-acoustic sensor. The developed setup exploits the advantages of mid-IR detection and introduces significant novelties in the key components, namely a non-conventional silicon racket-shapedcantilever, a combination of a dual-tube acoustic resonator and optical cavity to enhance the photoacoustic signal, and an improved optical readout system consisting in a stabilized balanced Michelson interferometer. With a final detection sensitivity of dry N2O down to 17 parts- per-trillion for 20 s of integration time, corresponding to a Normalized Noise Equivalent Absorption coefficient equal to 5.98 x 10-11cm-1 WHz-1/2, the achieved performance is in line with the best results obtained with PAS-based sensing addressing the same target molecule. This demonstrates the wide range of yet unexplored configurations of photoacoustic systems that can be exploited towards real-time sub-ppt sensors for practical detection of trace chemicals in the air.
Journal/Review: SENSORS AND ACTUATORS B-CHEMICAL
Volume: 430 Pages from: 137313-1 to: 137313-10
More Information: This work was partially supported by the European Defence Agency under the Cat-B Project Q-LAMPS Quantum LAser-based Multi para- metric Portable Sensor (EDA contract n.B-PRJ-RT-989), by EU NextGenerationEU Program with the I-PHOQS Infrastructure Integrated infrastructure initiative in Photonic and Quantum Sciences [IR0000016, ID D2B8D520] and the Qostrad Quantum-ehnahanced optomechanical sensors for trace gas detection Project under the National Quantum Science and Technology Institute (NQSTI) PE0000023 PNRR Pro- gram, the Laserlab-Europe Project [G.A. n.871124], the MUQUABIS Project [G.A. n.101070546] Multiscale quantum bio-imaging and spectroscopy, by the National Natural Science Foundation of China (NSFC) (8326015, 52122003) and by the Direct Grant for research from The Chinese University of Hong Kong.KeyWords: Photo-acoustic spectroscopy; Optical cavity; Silicon-based MEMSDOI: 10.1016/j.snb.2025.137313
