Nondestructive Inspection by Using Scattering and Spectra in Terahertz Waves

Abstract

In this paper, we show that the nondestructive detection of chemicals hidden in envelopes can be achieved using terahertz waves in a simple two-step procedure: First, scattering of the terahertz waves is an indicator of the presence of powders in the envelope; second, the identification of the chemicals is done by spectral fingerprinting. In addition, we examined the possibility of measurement by diffuse reflection.