Component analysis of chemical mixtures using terahertz spectroscopic imaging

We demonstrate the possibility of inspection of chemical mixtures by terahertz (THz) spectroscopic imaging using known spectral data Of the pure chemical components. This method, which is based on principle component analysis, can determine the existence of chemicals, identify them, map the spatial distribution of each component, and measure their content in a target. We determined qualitatively and quantitatively the components not only in pure chemical samples but also in mixtures. The content of each component determined experimentally comes in agreement with their respective known contents. (C) 2004 Elsevier B.V. All rights reserved.