Imaging standoff detection of explosives with broad band tunable quantum cascade lasers

In this work we demonstrate standoff detection of traces of explosives using midinfrared laser spectroscopy. We apply active laser illumination and use an infrared camera for collection of the diffusely backscattered laser radiation. The key component of the system is an external cavity quantum cascade. Different numerical hyperspectral image analysis methods are evaluated with respect to target detection performance and false alarm rate using both synthetic and real spectroscopic data.