Component Spatial Pattern Analysis of Chemicals Using Terahertz Spectroscopic Imaging

Abstract

We have developed a novel basic technology for terahertz (THz) imaging, which allows detection and identification of chemicals by introducing the component spatial pattern analysis. The spatial distributions of the targets are obtained from terahertz multispectral transillumination images, using absorption spectra measured with a widely tunable THz-wave source. First, the two kinds of chemical pellets were clearly distinguished. Next, we separated the component spatial patterns of frequency-dependent absorptions in chemicals and frequency-independent components such as plastic, paper and measurement noise in THz spectroscopic images. Hereby we expect this technology to contribute to the following potential applications: screening letters and packages, frisking, quality inspection of pharmaceuticals, and pathologic diagnosis.