A multi-gas sensor for environmental gases: towards miniaturization with mid-infrared Quantum Cascade Lasers (QCL) and silicon integration of photoacoustic cells

Abstract

Atmospheric composition varies both spatially and temporally, notably in terms of relative humidity and greenhouse gases. Current methods rely on massive and expensive sensors deployed sparsely. Here, we are interested in developing a multigas sensor that targets very small atmospheric composition variations. In addition, it intends to be gas specific, lightweight, autonomous and compact. Targeted gases are either greenhouse gases such as CO2, CH4 and N2O, or toxic gases such as CO and SO2. For this purpose, we have developed a Photoacoustic Spectroscopy sensor, using Mid Infrared QCL laser sources (Quantum Cascad Lasers), which achieve a very narrow spectral linewidth and have a good potential for miniaturization. We developed a dedicated electronic device to perform data acquisition. Our prototype begins its calibration phase in a laboratory environment, prior further integration for real time measurements.