Sensitive laser based stand-off system for mid-infrared explosive detection

Within the last decades the global architecture of security and the security risks of the society itself have fundamentally changed. In particular terrorist attacks showed that preventive measures are important for protecting critical infrastructures, both public and governmental institutions. The fast and reliable detection of explosive traces and contaminations is a crucial aspect for an improved safety standard. For this reason we developed at the DLR institute of Technical physics a new laser based stand-off system for explosive detection. The portable system is especially tailored for operational use by emergency task forces and can be operated by one touch operation. Based on a high-repetition rate tunable mid-infrared quantum cascade laser and a detection scheme which offers excellent noise performance we can achieve a very high sensitivity and a high signal-to-noise ratio. This makes it possible to detect traces of explosives on different background substrates within seconds and without direct contact of the material. First results of the experiment will be shown in the presentation