Coherent Real-Time Terahertz Imaging for Packages and Personnel

In today's environment of the global war on terrorism, there is a need to strengthen on-base and aviation security by developing next-generation inspection technology for detection and identification of concealed threats in packages and on personnel. Asthe Air Force utilizes the commercial shipping infrastructure for its worldwide shipping needs, such enhanced inspection technology is vital to base security. Contemporary portal security systems based on X-ray and magnetic screening are seriously limitedin their capabilities for detecting a variety of potentially dangerous materials - weapons made out of ceramics, plastics, or composites; explosives; and substances associated with chemical, biological and nuclear weapons. Coherent THz imaging (CTI)presents significant potential as a safe, non-ionizing probe for both personnel and packages with no health risks and enhanced capabilities for compositional analysis and automated recognition. Foster-Miller proposes to design and develop a laser-based CTIsystem to permit the real-time interrogation of packages and personnel in complementary transmissive and reflective modes. Phase I will demonstrate the efficacy of CTI to the problem at hand by building a table-top system to conduct detailed spectroscopicstudies of various harmful substances and develop appropriate signal processing software and hardware for the detection and identification of concealed threats. (P-030276) The successful development of a robust and reliable laser-based coherent THz spectroscopy and imaging system promises to create new markets for this unique non-invasive analytical tool in a variety of commercial and military applications. These includechemical detection for environmental sensing and process monitoring, gas phase analysis of flames for combustion diagnostics, moisture analysis of biomedical samples, and packaging inspection for quality control and security applications. The foodprocessing, biomedical imaging, pollution control, and semiconductor manufacturing industries will be major benefactors of this technology.