Towards optoelectronic detection of explosives

Detection of explosives is an important challenge for contemporary science and technology of security systems. We present an application of NOx sensors equipped with concentrator in searching of explosives. The sensors using CRDS with blue — violet diode lasers (410 nm) as well as with QCL lasers (5.26 μm and 4.53 μm) are described. The detection method is based either on reaction of the sensors to the nitrogen oxides emitted by explosives or to NOx produced during thermal decomposition of explosive vapours. For TNT, PETN, RDX, and HMX the detection limit better than 1 ng has been achieved.