Multi-Laser Line Raman Spectroscopy for Detection of Chemical Warfare Agent Simulants using a Reflective Spatial Homodyne Spectrometer (SHS)

F. Vasefi, D.L. Farkas, R.A. Norton, S. Hosseini
SafetySpect Inc., California, United States

Keywords: Raman spectroscopy, spatial Homodyne spectroscopy, WMD, explosives, forensic

Chemical warfare agents (CWAs) have been used increasingly against military personnel and civilians, due to the heightened threat of terrorist activities. Raman spectroscopy is one of the most suitable methods to address this threat, due to its significant accuracy in chemical analysis [1, 2]. We propose a new ultra-resolution spectroscopy method, and its extension into multi-laser line Raman spectroscopy, by operating in three spectral ranges (UV, Visible, and IR). We expect performance an order of magnitude better than current Raman spectroscopy technologies for each of the most important/relevant features: sensitivity, resolution, stand-off detection distance, size and cost. We intend to show the feasibility of SHS for detection of CWAs simulants by developing the first prototype and complete system performance model and characterization. The proposed novel spectrometer primarily developed at JPL consists of three sections: input optics, SHS interferometer, and the fringe imaging optics coupled to the FPA (See figure 1) [2]. It uses Fourier transforms, has high optical throughput (up to 35%) and wide field of view (~10 degrees); these impart unique high-resolution capabilities (down to 0.01 Å resolution at 266 nm and 532 nm and 0.1 Å in 1064 nm).