A New, Hand-Held, 1 to 5 m Standoff Analyzer for Real-Time Detection of Trace Chemical, Biological, and Explosives Substances on Surfaces

摘要

Real-time assessment of suspicious substances on surfaces is an important capability needed by warfighters/firstresponders. It is also important to perform these assessments without contact or spreading of the suspicious substance oruse of reagents. We present work conducted under DTRA and Army funding to develop a hand-held, 1 m to 5 m standoff,optical sensor which detects and classifies trace and bulk concentrations of a wide range of chemical, biological, andexplosives (CBE) materials in real-time and full daylight with a fully integrated analyzer weighing less than 12 pounds,including batteries.The sensor method described here combines the complementary chemical information of molecular bonds using Ramanand the electronic configuration information using fluorescence, with excitation below 250 nm. There are six mainadvantages of excitation below 250 nm compared to near-UV, visible or near-IR counterparts: 1) Solar blind detectionenabling standoff operation in full daylight; 2) Fluorescence-free Raman and Raman-free fluorescence enabling enhanceddetection and identification of target materials without mutual interference; 3) Resonance Raman signal enhancement forimproved Raman sensitivity; 4) Simplification of Raman spectra due to resonance enhancement, 5) Short penetrationdepth, providing physical separation of surface contaminant materials from substrate; and 6) Eye retina safe. Thesedetection capabilities are not possible with near UV, visible, or near IR sensors. A special feature of our sensor is theability to detect trace biological materials at standoff distances in real time.Photon Systems and JPL have developed these methods over many years, enabling instruments deployed to extremeenvironments on Earth and an upcoming lander mission to Mars in 2020.