Quantum Cascade Laser Detection of Surface Contaminants

Physical Sciences Inc. (PSI) proposes to develop and demonstrate a novel approach for the sensing of chemically contaminated material using recently emergent Quantum Cascade (QC) laser technology. The focus of the Phase I effort was the detection ofpersistent (non-volatile) chemical agents such as HD and VX on man-made surfaces. In this effort PSI implemented a prototype system and successfully demonstrated the feasibility of detecting thin films of the agent simulant SF96 at thicknesses of 0.5 ¿m(50 ¿g/cm2). The extinction of the laser light was found to exhibit Beer's law type attenuation in this coverage range, which is well below actionable levels. In Phase II we propose the development of a three laser system capable of detecting nerve andvesicant chemical agent films on natural and man-made surfaces at ranges up to 1 km. This system will be constructed for implementation on a ground-based vehicle. Construction of the system will be followed by a series of laboratory and field tests toevaluated the effectiveness of the method under a broad range of conditions. The system will be delivered to AFRL following the completion of the effort.