Terahertz Spectroscopic Radar Mobile System for Detection of Concealed Explosives

To address the U.S. Army need for new techniques for detecting concealed explosives, Physical Optics Corporation (POC) proposes a new 100 m standoff Terahertz Spectroscopic Radar (TSR) which uses terahertz (THz) molecular spectroscopy to detect the unique THz absorption wavelength signature of an explosive's outgassed material. This design exhibits the most decisive identification pattern of explosives, whose molecular vibration modes lie in the THz region. To detect these specific explosive identifiers, TSR's innovative design analyzes the retroreflected THz signals from targets rather than the transmitted THz signals common to the conventional spectroscopy performed inside a laboratory. The TSR design combines a wideband (1-20 THz) transmitter and a receiver spectrometer, built on a mobile station. Using a high-quality submillimeter wave radar to send high rep-rate (~100 MHz) THz probing pulses, we can identify not only the explosive but also the location of the target with spatial resolution better than 0.03 mm since our radar pulsewidth is faster than 100 femtosecond (fs). The average power of our source is exceptionally high (~100 W) compared with any other THz sources. In Phase I we will build a preliminary TSR prototype, while Phase II will focus on a full engineering prototype.