We report in this paper the feasibility of standoff chemical detection using quantum cascade lasers (QCLs) and photoacoustic technique. In the experiment, we use a QCL with an emission wavelength near 7.9 μm, an electret condenser microphone, and isopropanol (IPA) vapor as a safer experimental substitute of the explosive, RDX. The QCL is operated at pulsed mode and the laser beam focused on the IPA vapor sample. The photoacoustic sound wave is generated and detected by the microphone at a remote distance. With less than 40 mW laser power, standoff photoacoustic chemical detection distance over 35 cm is achieved.

Date Published: 3 June 2011
PDF: 6 pages
Proc. SPIE 8018, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XII, 80180R (3 June 2011); doi: 10.1117/12.884387

Published in SPIE Proceedings Vol. 8018:
Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XII
Augustus W. Fountain III; Patrick J. Gardner, Editor(s)