Remote Raman Spectroscopy of Explosive Precursors

Deep ultraviolet Raman spectroscopy measurements have been performed at the German Aerospace Center (DLR) with the aim of detecting traces (µg range) of explosive precursors. In this study a backscattering Raman system was set up and optimized to detect urea, sodium perchlorate, ammonium nitrate, and sodium nitrate at a 60 cm short-range remote detection. Sample were tested at 264 nm ultraviolet laser excitation wavelength to experimentally observe any possible trace over textiles samples. For each colored sample textile, Raman spectra were acquired and no background fluorescence interference was observed at this laser excitation wavelength. Detection limits and system sensitivity with an acquisition times up to 3 seconds for microgram traces are presented