Brimrose Technology has successfully demonstrated experimentally the capability to standoff detect the presence of explosives like RDX using photoacoustic spectroscopy (PAS) augmented with a novel high sensitivity laser microphone based on the pulsed photo-EMF laser vibrometer (PPLV). The high sensitivity Photo-EMF pulsed laser vibrometer still is under research and development.
We developed material processing technologies for fabricating fused silica diaphragms with varying thickness which were then integrated into the PPLV laser microphone possessing the minimally detectable sound wave pressure level of less than 33 μPa. We also developed quantum cascade laser chips emitting laser pulses at the wavelength corresponding to the absorption peaks of RDX powder. The picture on the right shows the assembled fused silica diaphragm. The back-side of the diaphragm which receives the impinging acoustic waves, including the PAS signatures of RDX. A US penny is used as a scale to gauge the physical dimensions of the assembled fused silica diaphragm.
The capability to perform standoff detection of targeted molecules and chemical compounds plays a strategic role in facilitating the planning and execution of various missions by the US Army. For more info, please contact us.