Experimental Set-Up for the Design of Deep Ultraviolet Raman Spectroscopic Applications for Standoff Detection of Hazardous Substances Frank Duschek, Emanuela Gallo, Christoph Kölbl, Anja Köhntopp, Arne Walter German Aerospace Center, Institute of Technical Physics, Im Langen Grund 1, 74239 Hardthausen, Germany Despite its immediate applications, selective detection of trace quantities of surface adsorbed chemicals, such as explosives, without physically collecting the sample molecules is a challenging task. Standoff spectroscopic techniques offer an ideal method of detecting chemicals without using a sample collection step. Though standoff spectroscopic techniques are capable of providing high selectivity, their demonstrated sensitivities often are poor. Especially, Raman spectroscopy promises highest selectivity, but a number of challenges have to be managed in order to succeed in the detection of tiny amounts of substances [1-3]. In order to manage standoff Raman spectroscopic challenges, i.e. retrieving spectral signatures of traces on an unknown, possibly fluorescent background, measuring in an open, public environment and under deep UV conditions, a basic setup for the standoff detection of trace quantities of surface adsorbed chemicals using deep UV Raman is described and characterized at an excitation wavelength of 264 nm. This set-up promises to be an aid for future, compact UV Raman equipment for standoff applications from ~2 m and above. EXPERIMENTAL In order to find best conditions for the design of standoff Raman applications, a flexible set-up has been chosen. The tunable laser (Continuum Sunlite) allows for UV Raman excitation at wavelengths down to 230 nm. The Raman scattering is collected by a 4’’off axis parabolic mirror and guided into the Czerny-Turner spectrometer, with a longpass laser line filter, 2400 g/nm gratings and a nitrogen cooled CCD. Figure 1 Experimental set-up for deep UV Raman standoff applications with a tunable solid state laser (230-1700 nm)