Terahertz (THz) spectral signatures have been measured for a variety of explosive materials and precursors. These
signatures were measured by THz Time Domain Spectroscopy, using ultrashort pulsed lasers coupled with electro-optic
materials to generate and detect THz radiation. Transmission and reflection spectra were measured across a frequency
range from 0.2 to 2.5 THz for solid and liquid materials. These spectra are reported in terms of index of refraction and
absorption coefficient, both of which can be calculated from transmission or reflection data. The value of THz spectral
signatures for the development of future explosives sensing systems is discussed.