Application of Quantum Cascade Lasers to High Explosive Detection

"Physical Sciences Inc. (PSI) proposes to develop and demonstrate a chemically-specific standoff sensor for detection of explosive materials within sealed containers, buildings, or clothing. Differential absorption LIDAR (DIAL) methodology will be used toprovide chemical specificity. Our innovation is the extension of DIAL technology to Far-IR (THz) wavelengths for enabling structure-penetrating radiation to probe molecular features of target substances. This technology represents a long-standing needwith the DoD, FAA, and security community for detection of explosive devices containing little or no metal concealed in trucks, luggage, packages, and under clothing. The Phase I program will demonstrate the feasibility of the concept through experimentalmeasurements of absorption spectra of target compounds and structural materials and the first demonstration of a current-pumped Quantum Cascade laser-based sensor in the THz frequency regime. In the Phase II portion of the program, a compact sensor willbe developed, tested, and delivered to the Air Force. This program will demonstrate a structure-penetrating DIAL apparatus with the capability of chemically- specific detection of explosive materials. Such an apparatus represents a long-standing need inthe military for the detection of hidden illicit materials. Significant commercial applications of the enabling sensor technology exist in the petro-chemical and bulk materials process