This work relates to standoff detection of nerve agent simulant using mid-infrared quantum cascade lasers (QCL) and photoacoustic technique. In our experiment, a mid-IR QCL with an emission wavelength near ~7.35 μm was operated under pulsed conditions. Gas phase nerve agent simulant was generated and calibrated using a vapor generator. The QCL output beam with average output power ~150 mW was focused on the gaseous sample in open-air environment. Photoacoustic signals were generated and detected by an ultra-sensitive microphone. With the help of a parabolic sound reflector, standoff detection of gas samples with calibrated concentration of 2.3 ppm was achieved at a detection distance of more than 2 feet. An extended detection distance up to 14 feet was observed for a higher gas concentration of 13.9 ppm.

Date Published: 29 May 2013
PDF: 8 pages
Proc. SPIE 8710, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XIV, 871007 (29 May 2013); doi: 10.1117/12.2016282

Published in SPIE Proceedings Vol. 8710:
Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XIV
Augustus Way Fountain III, Editor(s)