Compact, Wide Field Photoacoustic Explosive Detection

OPTRA proposes the development of an explosive detector comprised of a Risley scanner and a standoff photoacoustic detector for robot-based mobile operation. The Risley scanner is a mature technology, which uses a pair of matched prisms to steer a laser beam anywhere inside a cone. OPTRA has extensive experience developing and customizing such Risley scanners to accommodate a variety of applications including laser ranging, optical avoidance and optical communication. The standoff photoacoustic explosive detection hardware concept was developed at Oak Ridge National Laboratories (ORNL) and utilizes a Quartz Crystal Tuning Fork (QCTF) to detect reflected returns from the target. Using this technology, ORNL has demonstrated the ability to detect explosive concentrations as low as 100 ng/cm2 at a range of 20 m and to distinguish between various explosives. By coupling these two demonstrated technologies, OPTRA developed a breadboard system during the Phase I, which was demonstrated to collect TNT and RDX explosive spectra. During the Phase II, OPTRA will build on this success by developing a compact prototype system complete with detection and discrimination algorithms suitable for mobile standoff explosive detection. This highly sensitive, wide field explosive detector prototype will be capable of monitoring large areas from a safe distance, which should help neutralize the IED threat in the near term.