Multi-gas quartz-enhanced photoacoustic sensor for environmental monitoring exploiting a Vernier effect-based quantum cascade laser

• DOI: 10.1016/j.pacs.2022.100401
• Publication Date: 2022-09-05T23:40:06Z
• Authors: Andrea Zifarelli; Raffaele De Palo; Pietro Patimisco; Marilena Giglio; Angelo Sampaolo; Stéphane Blaser; Jérémy Butet; Olivier Landry; Antoine Müller; Vincenzo Spagnolo
• Keywords: QEPAS; Physics; QC1-999; Acoustics. Sound; QC221-246; QEPAS, Widely tunable QCL, Multi-gas sensing, Environmental monitoring; Environmental monitoring; QC350-467; 02 engineering and technology; Optics. Light; 7. Clean energy; Widely tunable QCL; Multi-gas sensing; 0210 nano-technology; Research Article

We report on a gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) able to detect multiple gas species for environmental monitoring applications, by exploiting a Vernier effect-based quantum cascade laser as the excitation source. The device emission spectrum consists of ten separated emission clusters covering the range from 2100 up to 2250 cm-1. Four clusters were selected to detect the absorption features of carbon monoxide (CO), nitrous oxide (N2O), carbon dioxide (CO2), and water vapor (H2O), respectively. The sensor was calibrated with certified concentrations of CO, N2O and CO2 in a wet nitrogen matrix. The H2O absorption feature was used to monitor the water vapor within the gas line during the calibration. Minimum detection limits of 6 ppb, 7 ppb, and 70 ppm were achieved for CO, N2O and CO2, respectively, at 100 ms of integration time. As proof of concept, the QEPAS sensor was tested by continuously sampling indoor laboratory air and monitoring the analytes concentrations.